4MEM Error during system diagnosis

Hi.
I got some problems with my unibody MB. I'd like to first try to find a solution here before calling the support.
For the last couple of days safari/firefox shut down randomly.
So yesterday I tried to download the new itunes update. During that: Error of Safari & Kernelpanic...
So I restarted the computer and nothing really happened. Tried PRam, removed the battery and held the powerbutton for a few secs.
After that...nothing happened. So I grabbed my DVD and 'checked' it with the disk utility. It appeared, but I couldn't even check the drive or the access rights...
So with my head pretty much on the ground I gave it a try and started it up again. And bingo. It seems to be alive since then.
With one error on the diagnosis programm (startup + d)
I got this error - and I can't find anything about it on the internet:


4MEM/1/40000000: 0x7a61cc18

I hope that anyone of you can help me. I would be very happy if 🙂

Greetings