No, your problem is almost certainly NOT what that MacFixIt article is talking about. The problem in that case would still only occur when the HD was full, which your screenshot indicates yours is not (not to mention the fact that filling 75GB of HD space with VM swap files would mean there was some application going absolutely berserk eating up RAM, and you'd be hearing a huge amount of disk activity).
The MacFixIt report was just commenting that a lot more paging tends to happen under Panther (which I haven't really experienced), but it's still just regular paging.
I'm assuming that it is indeed your startup partition with the 75GB free, in which case the problem is just weird.
Try running Activity Monitor, and watching the tab for RAM use (or just checking out what processes are using how much RAM), and see what's going on the next time that problem occurrs. Panther handles low HD situations much better than Jaguar, so corruption dosen't occur when swap files fill your boot partition (which happened to me several times), and maybe the trigger limit on your computer got screwed up somehow (that is, it panics on 75GB free instead of 75MB or something).
Also, out of curiosity, how much RAM do you have?