[petek]

Have you removed any non-original PCI cards you might have?

Have you tried doing the most basic system install (no drivers, no internet, etc.)? I forget what all the options are, but you want to do a minimum install.

Unless I'm mistaken, if it's crashing while checking packages it is before it actually starts installing files on your disk, though.

It probably isn't your problem but I know OS X is supposed to be very finicky about memory timing. I didn't have any RAM problems with my G3 with a variety of sticks (128 & 2x256 MB, all PC 100 CL2). There used to be some RAM test utilities on the web which came out when OS X first appeared. A lot of people had to get new RAM back then because cheap chips would fail Apple's test. You might check on xlr8yourmac.com and macnn.com forums.

BTW since the install my G3's been rock-solid with no crashes for at least a couple of months.