My parents (formerly myself) have a rev A beige G3 desktop, originally equipped with a 233Mhz G3 chip, that I have upgraded considerably. It has a OWC mercury G4 zif @ 466Mhz, a powerlogix USB/Firewire PCI card, a Acard AHARD ATA 66 PCI card, Apple-supported CD-RW, 512Mb of RAM, maxed the built-in video's VRAM to 8Mb, and then has a 30Gb Maxtor ATA-133 HD connected to the Acard ATA host. As long as I had it, it always ran OS 9 and Yellow Dog without a hitch, never a problem. When I gave it to my parents, I also got a OS X 10.0 install disk and installed that, then upgraded it to 10.1.5 and it runs that OS without a problem all the time- it's used daily and frequently and is one of the most stable machines I've ever seen. Then came the point of wanting to upgrade to Jaguar and the problems. The installer would freeze midway through the install every time. I tried putting the stock G3@233Mhz back in and installing, taking out the USB/Firewire card and installing, and installing on a clean blank drive all with the same result. Occaisonally I did get the installer to go most of the way and had a bootable system, but this was rare and the system wasn't complete and there were problems. Can anyone maybe spot an obvious or even not so obvious cause to the trouble? Thanx Much!