I'm in the process of migrating NDPS HP Printers from NW5.1 SP7 to a new
NW6.5 SP3 server.

Out of the 10 (all HP) printers switched over so far, three have stopped
working (HP Inkjet 2250TN, HP Laserjet 4000TN, HP Laserjet 2100TN).

The 2250TN only prints the 1st quarter of the 1st page and stops.
The 4000TN only prints out about eight pages.
The 2100TN is intermittant and usually only prints one page then stops
with a 40 EIO error.

All three were working fine on a NW5.1 SP7. What is so different with
NW6.5 SP3 to cause this?

I tried upgrading all three to the latest JetDirect firmware, but this
made no difference.

I managed to fix the 2250TN by replacing the automatic NDPS Printer
Driver with an older one. Then all PC's with *existing* NDPS printer
connections started working again! I could understand a bad driver would
cause problems for new NDPS printer installs, but why would this affect
existing connections?

Until I can resolve this, I have moved the other two printers back onto
the NW5.1 box. (They are now working again)

Long term the plan is to migrate to NW6.5 and switch to IPP, so I need
this to work!

Does anyone have a solution to this problem?

Thanks in advance