Symantec is warning that its Endpoint Protection Manager server product is erroneously marking signature updates issued this year as out of date.
Symantec's issue is one of few scattered reports of software problems related to the end of the decade, including one allegedly involving Microsoft's Windows Mobile OS.
The problem affects the Endpoint Protection v11.x and v12.x versions of the company's small business edition of the product.
Antivirus, antispyware and intrusion protection updates with a date after Dec. 31, 2009, at 11:59 p.m. are considered out of date by the software, the company wrote on its blog.
Symantec has worked around the problem by issuing updates with new revision numbers but with the Dec. 31 date while a permanent fix is developed.
The company said the problem also affects customers using NAC (Network Access Control) with Host Integrity, which checks to see if the antivirus definitions are up to date for clients connecting to a network. Symantec said the Host Integrity check will fail but there is a work-around, which the company details in its blog post.
The end of the decade may also be causing problems for Microsoft's Windows Mobile OS. Various sources have reported that some users running Windows Mobile 6.1 or 6.5 noticed that text messages sent after the new year are dated 2016. Although a work-around has been posted to WMExperts, other users on that forum reported no problems.
Microsoft said on Tuesday it was aware of the issue but that "these reports have not yet resulted in widespread customer inquiries."
"However, we are working closely with our manufacturing and mobile operator partners to investigate the cause and correct the issue as appropriate," according to a written statement.