I really need help on this too. I tried everything above, but in my case it looks like something is keeping it at a memory limit of 32M.
Allowed memory size of 33554432 bytes exhausted (tried to allocate 7680 bytes) in /home/mysite/public_html/blog/wp-includes/kses.php(550) : runtime-created function
My host tried bumping it up to 64M and 80M but the same thing, exhausted at 32M. Help!