Using two GTX260 with SLI. Having crash problems.

So this is more of a question at the moment. So I have two GTX260 cards connected through an SLI. I have been having various crash problems. Generally I'd boot up my PC normally, start up a game and once I am in game about 5-10 minutes in I'd sometimes lock up (no error or mini dump records) along with sound looping if sound was playing at the time. After that first initial crash, Id generally lock up most of the time at the Windows start up screen ( but have no problem with safe mode).

I've been trying to solve this issue here on the BSOD section of the forum and have been pointed to post here. Did a lot of troubleshooting, even did a clean install of windows 7 64 bit. It seemed fine once I reinstalled however when I started applying windows updates (which includes NVIDIA drivers) my system locked up again.

Yesterday I called DELL since I have a warranty and they had me unplug my system completely and disconnect my video cards and SLI. Then I reconnected everything (minus the SLI) and so far I have not had any issues. (Dell is sending me two new video cards and an SLI)

Now my question is this. Does this make sense? Or is this just a temporary "fix". I've had bad run ins with DELL and am very skeptical on if this is resolving the issue or not.

It's very possible that one or even both GPU's have gone bad. Or possible the SLI cable could be bad. Thats why they're sending out all 3 to you. If heard many of horror stories with all brands of off the shelf retail PC's. That's why I opted to build. You buy what you want and know that all hardware is compatible with each other, of course doing all the research before hand.

Thank you very much. A second opinion is what I needed. Like I said the system is running fine atm. Better then ever. Its just like I said, had one real bad run in once.