Microsoft's latest set of updates for Office XP is causing headaches for users of two junk mail filtering products.

After installing Office XP Service Pack 3 (SP3), users of Sunbelt Software's iHateSpam and Cloudmark's SpamNet are complaining about security warnings popping up with each email message they receive, according to reports on the Windows NTBugtraq mailing list.

Both Sunbelt and Cloudmark acknowledge the problem and have posted support bulletins on their websites. Sunbelt has released an update to its software to fix the problem while Cloudmark states it is working with Microsoft to solve the issue.

Office XP SP3 was released on Tuesday and contains security enhancements for the Office suite in addition to stability and performance improvements, according to Microsoft's website.

After installing SP3, each email received triggers a dialog alerting the user that a program is trying to access email addresses stored in Outlook and warning that this could be related to a computer virus. There is no indication of what program is accessing Outlook, according to the NTBugtraq posting.

Cloudmark received complaints from a handful of its customers and hopes to fix the problem soon, confirms spokeswoman Tricia Fahey.

"The people we have heard from have been consumers who use the desktop product. We are working internally and with Microsoft to resolve the problem before SP3 is widely deployed," she says.

Cloudmark's SpamNet is used by consumers and enterprise users. Customers include the New York City Department of Education, Honeywell International, Virgin Entertainment Group and Bertelsmann AG, according to Fahey.

Other applications may also be affected by the Office update, but no information about that was available at press time.