cpu freezes

I recently added 128mb of crucial memory,which was
8 chips instead of 16 (both sides of module)my other memory modules have the 16 chips, my question; the cpu freezes after a certain time the mouse is frozen as is the keyboard.

Could it be thatthe modules have to have the same amount of chips?

I have to reboot several times, if I leave the cpu on all day.

It seems when I try to get on the net with ie the window opens in ie, bur when I click the dial up connection, it freezes up, could it be ie?

Any help is greatly appreciated.

Cheezer