stack overflow Error: in routine alloca()

the search showed no results so i hope it’s not a dupe. i’m running 5.5.32-29.3 on debian 6.

now right after starting up, no matter if i use no-defaults or use my config, i get the following error:
Error: in routine alloca() there is a
stack overflow: thread 0, max 8180KB, used 57KB, request 146B

as you can see the default ulimit stack size is 8192. when i set it to unlimited it runs but not very stable. meaning it restarts after a couple of hours and quite some tables end up marked as crashed. i also lose all connections with all related programs which use permanent connections.

so obviously my question is: what’s wrong there?