The nice thing about Google is that if you have a tech support problem, you can copy and paste the error and find 10 other people who had the problem. Perfect example is the worst debug message in recent memory, AOL's: feedbag error.
I just rebooted after some fairly big tweaks, including upgrading to 10.3.4, and I get the error I pasted in my title bar. Related to the Unsanity/Panic stuff? Doubtful. This is the Mail.app, which hasn't been touched. The 10.3.4 upgrade is probably more likely. I just can't seem to find anyone with answers in Google.