I just installed a gigabyte of ram in my TiBook 667MHz (from late December '01, top-of-the-line at the time). When I go into system profiler (Panther) and click on memory it says under speed for each Dimm: PC-100 222S It said this previously when I had 2 x 256MB Ram (stock). I assumed that Apple had given me PC-100 RAM, even though my bus speed is 133Mhz. I purchased 2 x 512mb Apple-Samsung PC-133 RAM to replace the old memory, but it still says that the ram is running at PC-100 (the sticker on the outside of the new RAM modules says PC133). Anyone else have this problem, or any advice?