Hardlocks (This is a bit long, sorry)

I am having a problem with a system I built recently.

When playing games such as CC: Generals and Planetside, the system will randomly hardlock (screen freezes, sound system makes a horrible screeching noise and then loops the most recent audio about 2 seconds back, or sometimes no audio at all) and the only way to get out of it is to hit the reset button on the case. I have NEVER had a crash when doing normal operations such as web browsing or word processing or playing mp3's. My system specs are:

- Asus P4C800 Deluxe

- Intel P4(C) 2.6ghz (Thermaltake A1545 P4 Spark 7 for cooling)

- Corsair TWINX512-3200LL 512MB DDR400 XMS3200 Ultra Low Latency Dual-Channel Memory

- ATI Radeon 9600 PRO

- Creative Labs SB Audigy 2

- Western Digital Caviar WD1200JB

- Antec TruBlu 480 watt PSU

- Windows XP (Pro)

Now, originally I though it was an overheating issue, so I picked up the Thermaltake CPU cooler, and the case now has two 120mm fans (one suck, one blow) and a pci slot fan next to the ATI card. At idle, my cpu and mobo are at about 75 degrees, under load, they never exceed 105 degrees.

I also thought it may have been the audio subsystem on the mobo causing it, so I installed the Audigy 2. No help there.

I assume it must be a memory issue. My friend built a system that had an Asus mobo that used rambus memory, and he found that it was extremely picky about what brand of memory it used. I have tried running memtest86 and the program has never completed all the tests. It always crashes, but always at different spots of different tests.

I thought I saw a post on here a while ago that said Kingston HyperX memory worked well on Asus boards. I wanted to check with you guys, to see if there is anything else I overlooked before I went and bought a gig of memory (I might as well upgrade right? :) )

To sum up: - Any other causes for the hardlocks?
- Any known compatibility problems with Asus/Corsair or Asus/Kingston
- Can you believe how long this post is?

I have learned alot from this board...any help would be greatly appreciated.

I also forgot to mention I have all the most recent BIOS for the mobo and drivers for everything else.

I'd definitely look at the memory if it doesn't pass Memtest.

I'm sure you can get a replacement if it's still under warranty.

I ordered some new memory from Kingston, their valueram line, that should be here tomorrow morning. I will let you know how it goes.

That memory works great for me.

My ddr400 is oced to ddr440 and can do ddr450. Impressive for so called "value ram".

The only difference is the timings are very loose. CAS 3 at stock speed (Recommended. Can do 2.5 if I'm not mistaken)

Well, good news and bad news.

My new ram works great. Memtest will run now, but I do have a question about it. How long is it supposed to run? It said it had gone through three passes before I finally stopped it. Is each pass a complete test cycle? Any info would be appreciated. On a positive note, it said I had no errors at the point that I stopped it.

Thanks guys.

(now that this thing is stable, I will try some mild overclocking)

I usually let it go for 2 or 3 passes because it happened to me that it didn'T fin errors on the first pass, but did on the second.

Once you have found your wanted settings, you can run it for an hour or two to be 100% sure that the RAM works perfectly.

Also, you can run the complete tests which takes more time.