I just got a G4 Sawtooth. I upgraded the hard drive from a 27 GB ATA 66 to a Segate 40 GB ATA 133 but didn't upgrade to a new controller card. I also added a stick of 128 MB PC 100 and 2 Sticks of 64 MB to get me to 512 MB of ram. I also installed a retail version of Panther. My Issue is that everytime I have more than one app open my mac locks. I can't even do a force quit on the apps, it just dies. Could this have anything to do with having an ATA 133 drive working at ATA 66 speeds. Or do I need more ram to make it run right. Thanks for the help.