Hi, I've posted before on this issue, but at the time I thought that the random freezes with my new G5 1.6GHz system were due to some 3rd party RAM (tried Apacer and Kingmax) that I had installed. I've since removed the RAM, but my freezing/lockup problems have continued. Basically, the symptoms are fairly simple: just navigating around the desktop, using Safari, or reading e-mail with Mail is enough to occasionally lock the entire system up. Nothing is written into the /var/log/system.log or to the console which would indicate something going wrong. I have run the Apple Hardware Test, in both quick and extended modes, but no problem is reported. I also performed a 'erase and install' new installation of Mac OS X 10.2.7 from the provided DVD. The system actually locked up *during the installation*!!! At this stage I called Apple Australia, and started speaking to their support people. Their first suggestion was to re-install again, but this time deleting the original partition and re-partitioning. I did this, but once again, the installer locked up at the 'Registering your Details with Apple' stage (those little animated blobs just froze too...very sad. The G5's fans also kicked into high gear, indicating that the OS had lost control of the hardware). Another call to Apple, and this time the suggestion was to boot into single user mode and perform an fsck (it came up clean), and then to reset the CUDA switch on the motherboard. That was about an hour ago, and since then, i've been running iTunes, surfing the web with Safari, and reading email with Mail with no problems...all the things that made the system lock up before. I've even given UT2003 a quick run, and it all seems fine. Maybe the CUDA reset was what fixed it. Maybe it's just so random that 5 minutes after I post this message it'll lock up again? I don't know...I'm pretty concerned that my 6-day old G5 system is so unstable. This is the sort of behaviour I would expect from a bottom-tier PC clone with dodgy RAM. Has anyone out there had similar experiences with their system locking or freezing up, even *without* adding in 3rd party RAM or PCI cards? This thing is as stock as the day it arrived. The config is: 1.6GHz G5, 256MB RAM (2 x 128MB), 80GB HDD, Combo drive, Radeon 9600 Pro, no modem, no Airport, no Bluetooth, stock Apple mouse and stock Apple keyboard, connected up to a 17" VGA screen via the supplied Apple DVI->VGA adapter. Mat.