Good thing I switched hit counters when I did!
Trying to get to Fr. Z's blog and other blogs, I had encountered this error message:
At first I thought it was me, as several blogs sent that error message. It turns out that blogs and website that have Sitemeter loaded are generating this error message to Internet Explorer users. This info is coming from Diane at Te Deum Laudamus (the screenshot above is Diane's as well). She removed Sitemeter, and her blog is now working fine.
Incidentally, I switched hit counters months ago, thank God!
UPDATE: Diane left a link to a list of Google News stories on Sitemeter's chaos in the combox.