RAM problems??

Modern Angel

I've just done a totally clean install of OS 10.1 on my 400 Mhz G3 Powerbook Lombard (bronze keyboard) with 64 megs of built-in RAM and a 128 meg stick of Crucial RAM. Problem is that whenever I have the crucial RAM installed the OS will either hang at startup or after a half an hour or two of use. When I take that crucial stick out it runs fine but only with 64 megs or RAM.. (blech... )

I've called Crucial and they've sent me a new stick of RAM but it still does the same thing.. grrr.. anyone have an idea of what might be up?