Today I experienced the same problem: "A General System error occurred" pops up, without any other info, when selecting the Events tab in VIC. It sometimes happened on the Perfomance tab, too.
Earlier a weird thing had happened. I had opened the console to my FreeBSD system, as it needed rebooting for some maintenance, as suddenly the VM hang inexplicably (something which has never happened before). Perfomance tab indicated a permanent 100% CPU usage (whereas it should have just been idling on a prompt). So, after 5 mins I forcibly, and grudgingly, shut down the VM, and rebooted it. Everything went fine it seems, until I clicked the Events tab, and got the "A General System error occurred" error. The Event tab, at this time, had been completely wiped clean.
Like jimfitz, I suspected, while nothing other seemed out of the ordinary, that this might nonetheless be an indicator of a bigger problem. So I brought down all VMs, and rebooted the host. Now the Event tab had entries again (just one or two, after the clean start, it seems) and the error no longer took place.
So, the upshot of it all, is that apparently something went awry in the Event log manager/daemon (or whoever it is called), but since the error message is so non-telling (see next paragraph), there's no real good way of debugging it.
N.B. As putting folks in front of a firing squad is kinda illegal, could you guys at least just fire the guy who though "A General System error occurred" was a descriptive way of indicating errors? 
I mean, seriously, this error pops up on all sorts of issues, ranging from these kind of errors to the dreaded licence expired case. I even logged into the ESX host shell, to check /var/log/messages and such; but however well I searched the place, no additional info was to be found. I really hope that, come ESX 4.0, someone with slighty more fantasy will be in charge of coming up with descriptive error messages.