It would be useful if you could post your code, or provide a link to it (as a .txt file).

I have not come across this myself although it seems like it would happen if you are doing something pathological (meant in a good way :). If you can figure out where this problem is happening (chop you script up into bits, put print statements into it, comment out code etc.) this will help us help you more quickly. Or maybe you will see the answer right away. Especially if you are doing anything you aren't sure about, or that might be putting heavy demands on the system (recursion, tons of arguments, whatever).