Diamond Viper 2600XT will not work with Winsat

I have a Diamond Viper 2600XT 512MB PCI Express video card and I can't seem to get it to work with Windows Vista's Winsat or Windows System Assesment tool. It comes to the media palyback testing phase and the screen goes black and no signal is indicated the computer doesn't crash though. It then needs to be rebooted and everything is fine. Everything else works fine games windows etc. No problems. I contacted Diamond about the problem and after up and downgrading drivers the tech came to the conclusion my CPU speed was not fast enough for the card. Which is probably one of the stupidest things I have ever heard. I have a E6550 Core Duo processor a 430W power supply 2GB of ram. The specification for this card are at least 512MB of memory 400W power supply or higher and a Pentium 4 or AMD Athlon processor so I was sure I was safe. According to the tech I need at least a 2.4 GHZ processor speed or he will not help me. I wrote a fairly pointed reply and don't expect much help from him again. I thought I would appeal to someone with a little more intelligence to solve this issue. If it ends up being the processor speed that's fine this is the last ATI card I will buy. I never had trouble with NVIDIA and their specs are clearly marked. Sorry for the rant. Any help you can provide would be greatly appreciated. Thank you.