Memory leak

[Gaijin]

This just sounds as your loop is obviously way too big.
I have a Function which converts Strings of any length to HEX, since the function runs a loop through the string checking each character and converting it, the function uses over 2 MB for smallest texts.

Either try to find an another way to execute that much SQL commands or reduce them.
You could also use Ajax to execute the commands in smaller packs..
Posting the code could show some errors.... ;)