If you have, say, around 10 events scheduled to run at the same exact instant (hey, I thought it was a good idea to have all of them run every hour on the dot), bad things happen occasionally. One time Toolfish was hogging 98-99% of the CPU when several events failed to run correctly, like when closing down it said "There are 5 events currently being run, please wait while they finish up....."

I waited for a few minutes when it did this, but it still didn't finish up, so I used Force Shutdown.