Intermittent boot problems when adding memory

[DolphinJay]

Today I just tried to add some memory to my second machine. It has a Micronics C300 MB(LX Chipset). It originally had two 32 mb pc100 dims double sided in dimm slots 1 and 2. I tried to add 128mb pc100 dim also double sided into dim slot 3. When I first added it the comp booted fine and windows and bios showed 192 MB installed. But after cold boot to make sure, it did one long beep and then quick beep beep beep. Then nothing no video or anything. I did the cold boot about 6 times and it would only get past the POST twice. So I pulled the two 32 mb dimms out and the comp runs and boots fine with just the 128 dimm installed in slot 3. I never heard of a comp having intermittent problems. The new memory either works in the configuration or it doesnt. Am I doing something wrong. Thanks for any help