Hello everyone, I'm new to this forum. I'm troubleshooting a video editing lab where I work that runs 5 G5s with dual processors and 8GB of RAM in each, as well as OS X 10.4.2. The IT tech for the lab put the same image on all of the machines. They all tend to crash in iMovie when doing heavy audio work (so I'm told, I haven't been able to catch one do it, but have only seen the crash logs). One in particular gets kernel panics quite often. I've thrown out the preferences, reseated RAM and so on, but the problem continues. I ran memtest on a couple of them and noticed that both failed the block sequential test (I'm betting that if I were able to run the test on the others that they would fail as well). The IT tech purchased all 8GB of RAM from a 3rd party vendor - MacRAMDirect.com (HyperVelocity RAM). I'm curious if anyone else has had problems with this RAM or maybe that I'm looking in the wrong direction. The instability and especially the results of the memtest leads me to believe that there is a RAM imcompatibility issue since every machine is having the same problems. If anyone could help I would be very appreciative.