Don't know if you've seen this one or not Trick, but I've gotten it a few times on two different computers.
"Fatal error: Out of memory (allocated 524288) (tried to allocate 311296 bytes) in /home/slforum/public_html/Sources/Subs.php on line 1788"
The solution thus far has been to either hit refresh, or go back and reclick the same link.
I was just getting ready to post something about this. There appears to be some memory issues with the database (or other components) not releasing memory the way it should be. I have a ticket open with the host, if need be I will have the memory upgraded ASAP. More to come...