my friend's father bought his old iMac (350 Mhz slot loading w/ 100 Mhz system bus) 512 MB of ram ( two 256 MB dimms). But, he bought PC133 ram and insists taht he was told it was the right memory. I said it qont, but he wants to be sure. Is PC133 ram backwards compatable w/ a PC100 system? The exact spec on the package are: Simpletech 256 MB PC133 168 pin unbuffered non-ecc sd ram dimm memory module Please answer quickly!