Somehow, in the six years after switching from using ICQ to Instant Messenger (and in the past two years Trillian which functions on the AIM network), I had amassed over 200 contacts. (Although, a bunch of them were added to my computer surreptitiously while I was in California—but that’s besides the point.) I decided to go through and get rid of people I haven’t seen online in years and people I haven’t even talked to in more than a year or so.
Apparently there’s some issue when you have more than 200 contacts in Trillian where you don’t see when people are actually online. Now that everything’s cleared up, it seems to be working much better.