outlook clients constantly asking for password

I am not sure whats happened, but all of a sudden all our outlook clients (mix of 2007 and 2010 on exchange 2007, sbs 2008) have started asking for a password constantly. the 2007 clients wont even accept it once its in, whereas the 2010 clients just have it pop up at regular intervals.
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Albert van der MerweIT TechnicianCommented:
Sounds like a possible dns issue
Can you check for Autodiscovery.. if it is pointing correctly.
Seems to be related to KB2553248.  Uninstalling worked as a temp fix for me.

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Magnus BIT-supportCommented:
Try turn off Application control on your Antivirus software and see if it disappears

can you check and uninstall KB2553248 from the client and check if this resolves..

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How many clients?

Have you tried on one computer- pull it from the domain and then re-add it to the domain and see if outlook gives the same problem?

Also, try re-creating the outlook profile on one computer and see if it works.

Check to see if all the computers are update with MS updates.
Neal58Author Commented:
ok cool, going through demazter's guide at the mo, I cant seem to find KB2553248 installed on any of the pcs.
WORKS2011Managed IT, Cyber Security, BackupCommented:
If you're on Exchange 2007 SP2 going to SP3 will resolve this.
Neal58Author Commented:
yeah still on rollup 6 so this may take a few reboots!
Neal58Author Commented:
pile of updates did the trick! will try and keep more up to date in the future
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