All of our systems are Windows 7 Enterprise 64bit.
We deployed over 100 systems with the 5.94 client.
First thing I tried, was deploying a bundle to those machines to run the silent installer for 5.98. This fixed the issue for maybe 30%.
We had several support calls for "printers disappearing", so I started directing clients to just run the install for 5.98 themselves from our print servers pcontrol.htm page. This fixed another 50%.
I still have about 20% of our systems where after both steps, the spooler keeps crashing when the workstation has been on for a bit and they try to print.
I noticed through software inventory that these systems still reported 5.94 in the Users\[username]\Appdata\Local\Temp\RarSFX0 folder, but registered 5.98 in the Windows folders.
I went as far as to remove all network printers, then uninstall the iPrint agent, and then delete the RarSFXO file, then reinstalling the 5.98 client and the network printers. It still did not fix these remaining systems.

Here is the ippErrs.txt from a system updated to 5.98. that is still losing the spooler.
9/30/2014 - 3:55:35 PM
Module: setupipp.exe
Trace Info: h:\bld\ndps\clnt_t~1\setupipp.exe\src\comstuff.cpp , line 407, thread 000010A0
Routine: CheckForHotfix - Hotfix KB2511290 was not installed
Error: The operation completed successfully.


9/30/2014 - 3:55:43 PM
Module: setupipp.exe
Trace Info: registry.c, line 2459, thread 000010A0
Routine: CheckPrintProviderInstalled - RegOpenKeyEx failed 2
Error: The system cannot find the file specified.


9/30/2014 - 3:55:43 PM
Module: setupipp.exe
Trace Info: h:\bld\ndps\clnt_t~1\setupipp.exe\src\comstuff.cpp , line 330, thread 000010A0
Routine: DeleteShortCut - DeleteFile failed 2
Error: The system cannot find the file specified.


9/30/2014 - 3:55:43 PM
Module: setupipp.exe
Trace Info: h:\bld\ndps\clnt_t~1\setupipp.exe\src\comstuff.cpp , line 330, thread 000010A0
Routine: DeleteShortCut - DeleteFile failed 2
Error: The system cannot find the file specified.


9/30/2014 - 3:55:43 PM
Module: setupipp.exe
Trace Info: h:\bld\ndps\clnt_t~1\setupipp.exe\src\comstuff.cpp , line 330, thread 000010A0
Routine: DeleteShortCut - DeleteFile failed 2
Error: The system cannot find the file specified.


9/30/2014 - 3:55:44 PM
Module: setupipp.exe
Trace Info: install.c, line 3982, thread 000010A0
Routine: MyRemoveFile - DeleteFile failed 2
Error: The system cannot find the file specified.


9/30/2014 - 3:55:44 PM
Module: setupipp.exe
Trace Info: install.c, line 3982, thread 000010A0
Routine: MyRemoveFile - DeleteFile failed 2
Error: The system cannot find the file specified.


9/30/2014 - 3:55:44 PM
Module: setupipp.exe
Trace Info: ippmain.c, line 22190, thread 000010A0
Routine: StartupLoginEventProcess - OpenThreadToken failed 1008
Error: An attempt was made to reference a token that does not exist.


9/30/2014 - 3:55:44 PM
Module: setupipp.exe
Trace Info: registry.c, line 2459, thread 000010A0
Routine: CheckPrintProviderInstalled - RegOpenKeyEx failed 2
Error: The system cannot find the file specified.


9/30/2014 - 3:55:51 PM
Module: setupipp.exe
Trace Info: ippmain.c, line 22333, thread 000010A0
Routine: StartupTrayIconProcess - OpenThreadToken failed 1008
Error: An attempt was made to reference a token that does not exist.


9/30/2014 - 3:55:51 PM
Module: setupipp.exe
Trace Info: registry.c, line 3442, thread 000010A0
Routine: AreDosboxPortInUse - RegOpenKeyEx failed 2
Error: The system cannot find the file specified.


9/30/2014 - 3:55:52 PM
Module: spoolsv.exe
Trace Info: ippmain.c, line 855, thread 00001ABC
Routine: IppCreatePrinterRef - Called on Loopback PING
Error: The filename, directory name, or volume label syntax is incorrect.


9/30/2014 - 3:56:50 PM
Module: iprntcmd.exe
Trace Info: registry.c, line 4751, thread 000003B4
Routine: GetUserServerVersionData - RegOpenKeyEx failed 2
Error: The system cannot find the file specified.


9/30/2014 - 3:56:52 PM
Module: spoolsv.exe
Trace Info: registry.c, line 4276, thread 00001520
Routine: FindDriverAndGetInfo - RegOpenKeyEx failed 2
Error: The system cannot find the file specified.


9/30/2014 - 3:57:28 PM
Module: spoolsv.exe
Trace Info: registry.c, line 4276, thread 00001520
Routine: FindDriverAndGetInfo - RegOpenKeyEx failed 2
Error: The system cannot find the file specified.


10/1/2014 - 8:23:47 AM
Module: spoolsv.exe
Trace Info: mytcp.c, line 538, thread 00001838
Routine: TCPRecv - failed to recv (socket 1640) TIMEDOUT(10060)
Error: Winsock 10060 - Connection has timed out.

10/1/2014 - 11:12:12 AM
Module: spoolsv.exe
Trace Info: ippmain.c, line 19228, thread 00001734
Routine: IppConnect - gethostbyname failed (error=11004)
Error: Winsock 11004 - The DNS name has been found in the database, but its associated data is not correct.

10/1/2014 - 11:12:13 AM
Module: spoolsv.exe
Trace Info: mytcp.c, line 183, thread 00001734
Routine: gethostbyname failed (error=11004)
Error: Winsock 11004 - The DNS name has been found in the database, but its associated data is not correct.

10/1/2014 - 11:12:13 AM
Module: spoolsv.exe
Trace Info: ippmain.c, line 19228, thread 00001734
Routine: IppConnect - gethostbyname failed (error=11004)
Error: Winsock 11004 - The DNS name has been found in the database, but its associated data is not correct.

10/1/2014 - 11:12:13 AM
Module: spoolsv.exe
Trace Info: mytcp.c, line 183, thread 00001734
Routine: gethostbyname failed (error=11004)
Error: Winsock 11004 - The DNS name has been found in the database, but its associated data is not correct.

10/1/2014 - 12:07:46 PM
Module: spoolsv.exe
Trace Info: mytcp.c, line 538, thread 00001890
Routine: TCPRecv - failed to recv (socket 1724) TIMEDOUT(10060)
Error: Winsock 10060 - Connection has timed out.

10/1/2014 - 1:54:12 PM
Module: spoolsv.exe
Trace Info: ippmain.c, line 19228, thread 00000BB4
Routine: IppConnect - gethostbyname failed (error=11004)
Error: Winsock 11004 - The DNS name has been found in the database, but its associated data is not correct.

10/1/2014 - 1:54:12 PM
Module: spoolsv.exe
Trace Info: mytcp.c, line 183, thread 00000BB4
Routine: gethostbyname failed (error=11004)
Error: Winsock 11004 - The DNS name has been found in the database, but its associated data is not correct.

10/1/2014 - 1:54:12 PM
Module: spoolsv.exe
Trace Info: ippmain.c, line 19228, thread 00000BB4
Routine: IppConnect - gethostbyname failed (error=11004)
Error: Winsock 11004 - The DNS name has been found in the database, but its associated data is not correct.

10/1/2014 - 1:54:12 PM
Module: spoolsv.exe
Trace Info: mytcp.c, line 183, thread 00000BB4
Routine: gethostbyname failed (error=11004)
Error: Winsock 11004 - The DNS name has been found in the database, but its associated data is not correct.

10/2/2014 - 7:34:02 AM
Module: spoolsv.exe
Trace Info: auth.c, line 2102, thread 00001A0C
Routine: SessionManagerGetCurrentUserInfo - @SYSTEM - SNMP PROBLEM
Error: Cannot perform this operation on this built-in special user.


10/2/2014 - 10:59:46 AM
Module: spoolsv.exe
Trace Info: mytcp.c, line 538, thread 000014C8
Routine: TCPRecv - failed to recv (socket 1728) TIMEDOUT(10060)
Error: Winsock 10060 - Connection has timed out.

10/2/2014 - 10:59:46 AM
Module: spoolsv.exe
Trace Info: ippmain.c, line 855, thread 000014C8
Routine: IppCreatePrinterRef - Called on Loopback PING
Error: The filename, directory name, or volume label syntax is incorrect.