System Behaving Erratically on Q6600

[Lord_Jeremy]

A few weeks ago I installed iAtkos v7 and everything seemed to be working smoothly. The only issue I had was the system would not boot with any IDE devices attached, so I switched to a SATA optical drive. In these past few weeks, a number of issues of increasing severity have appeared. The first thing to happen was sometimes the system would hang at the grey apple and verbose mode would give me a "still waiting for root device." Eventually the system would boot but no USB devices would work. This was fixed simply by restarting. Sometimes it would even take a second reboot. Then one day, I was browsing the internet and suddenly Safari stopped loading web pages. I noticed that Little Snitch's network monitor showed zero activity. When I tried to quit Safari, it hung and not even the Force Quit box would appear. I had to force restart the machine. Since then every few hours it seems the network connection dies and the system hangs. I tried removing all network drivers except those necessary for my hardware but that hasn't helped. On occasion when I'm playing a video file, the playback will suddenly skip around and QuickTime will crash. I should note I have Perian installed but I have had no problems playing the same files on a MacBook Pro with Perian installed. Just the other day, I was playing a MIDI file in QuickTime and suddenly it got all garbled and QuickTime crashed. Now whenever I play MIDI files their tempo fluctuates randomly. The first time I tried to launch WaveBurner it gave me a dialog box saying "Error while initializing the Audio Engine, WaveBurner will quit now." I'm using VoodooHDA. I've made no significant changes to the system that would precipitate these problems. I didn't use Snow Leopard because I ran into problems loading the install disk and I was worried that I wouldn't be able to get my video card to work. I have a GeForce 9400 GT with QE/CI supported. I really don't want to install because I don't have another hard drive and it would be extremely difficult and annoying to migrate all of my files over. I haven't yet upgraded to 10.5.8. I have a Time Machine backup of most of my files, I had to exclude certain large things because my backup disk is currently smaller than my internal disk. I'm pretty much wondering what people would recommend. Is there some Archive and Install-like feature I can take advantage of? Could this be a problem with an unsupported CPU? Should I reinstall Leopard? Should I try Snow Leopard? Thanks!