We have deployed a printer fleet using iPrint. The iPrint technology is working and we have over 3000+ client machines printing through the iPrint PrintManager which has about 230 Printer Agents attached. The server is a fresh install nw65sp7. (All other eDir servers are nw65sp6+.) The iPrint client is 4.32. The UniqueID attribute has been populated for all users. All users are uniquely named for contextless login. It seems that LDAP queries return no more than one result. All client machines are winXPProSP2, have client32 4.91 sp2 or sp4 and 80% are laptop/tablets, 20% are desktops. Printer Agents are secured with a medium setting and all rights are verified for the user's access.

Despite this setup working for most we are having trouble with persistent (yet intermittent) failure of automatic authentication with the iPrint client for an estimated 100 users. It is not that authentication never happens for a user. They are troubled by the constant return of the authentication dialog box. If a user repeatedly enters correct credentials (even with remember box ticked) up to ten times the job will print and/or the status of printers will be displayed in "Start|control panel|printers and faxes" changing from opening to ready.

We have tried reinstalling the iPrint client, logging on wireless and wired and/or ensuring no files are left in the c:\NDPS\DRV_TMP\ folder. Also restarting the spooler using TID 3672306 seems to get some users sorted out at a helpdesk level. I have not been able to narrow the occurrences to time frame, machine model, user type, user behaviour or other clues.

I've been looking at this for too long and need a fresh pair of eyes. I need some advice to sort this out at the enterprise level. I have attached a log sample to start but I am happy to supply more as requested. Thanks.

Is it corruption of data?
Is it LDAP timeouts I should be looking at rather than iPrint? iPrint gets its auth creds from client32 using a dll?
Is it a DNS issue? NDPSM is running with the NDS switch applied.
Lots of info at TID10097177: Ive covered a lot but dont think Ive exhausted all options.

Apache log attached

Documents related
IPrint Authentication Issues - CoolSolutionsWiki
Cool Solutions: iPrint Troubleshooting