I have had a similar track record with my upgraded cube. It has a 1ghz upgrade in it that just fights with leopard. It won't sleep properly and it freezes once a week (kernel panic screen 50% of the time).
When it runs in panther, 90% of the issues disappear. There is still the occasional freeze, without KP screen, making me think it is a heat issue.
That doesn't help much with the rhyme or reason, but reinforces the weird panther-ness.
Another item which I found helped a good bit, was doing the good ole nvram reset in OF. From my understanding, PRAM zap should clear this as well, but I have always had better success doing both than just one or the other. If I do this on the cube about once a week, it keeps it from having it's issues almost entirely. I feel like a car mechanic on a very picky sports car.
TBird
When it runs in panther, 90% of the issues disappear. There is still the occasional freeze, without KP screen, making me think it is a heat issue.
That doesn't help much with the rhyme or reason, but reinforces the weird panther-ness.
Another item which I found helped a good bit, was doing the good ole nvram reset in OF. From my understanding, PRAM zap should clear this as well, but I have always had better success doing both than just one or the other. If I do this on the cube about once a week, it keeps it from having it's issues almost entirely. I feel like a car mechanic on a very picky sports car.
TBird