Over the past couple of days I've heard from a number of people seeing a Windows Security Center warning that's causing them to worry that their system is vulnerable to attack.
Here's the warning:
"<program name> is on but is reporting its status to Windows Security Center in a format that is no longer supported. Use the program's automatic updating feature, or contact the program manufacturer for an updated version"
Here's what it looks like:
The issue seems to come down to an API change in Windows Vista SP1 as detailed here (it also applies to Windows 7). Your system is still fully protected against malware and for most people the message goes away after updating the application.