Ram / Logic board / Hardware problems?

Hey guys,

I'm having trouble pinpointing why my browsers and itunes all crash at random intervals.

I've used safari, firefox and chrome and they all crash so often. e.g. I click on firefox it launches and crashes. Doesn't go away until I try again perhaps 30 mins later.
My chrome individual tabs have been crashing as well.

I did a complete reinstallation twice with snow leopard / lion but neither fresh start works. Often the crashes will occur more frequently with time.

All my symptoms fit perfectly with bad ram. However I cannot prove bad ram because I pass both the memtest86 and apple hardware test extended loop more than 3 times for each.

I'm lost between deciding if there's a memory failure or logic board failure. What do you guys think?

 

Current ram is maxed out in 2 x 2GB configuration.

Haven't found any problems with the hard drives. I've swapped 2 different hard drives (for reasons unrelated to the problem) and I'm still facing the same issue.

I used to get kernal panics very often as well but it kind of faded away. Currently so used to facing different problems / crashing I no longer attempt to find fix for them and they just come and go.

Very keen to fix the problem before June this year as that's when my applecare expires.

 

Sorry about that

Macbook Pro 5.5 Mid-2009
13"
Core 2 Duo 2.26GHZ
2 x 2GB DDR3 Ram
Western Digital Scorpio Blue 500GB 5400RPM

Using OS X Lion 10.7.2

 

I've gone with my hunch so far and swapped out the RAM.

Appears that the problem has gone away for now and fingers crossed that it stays that way.

If the problem persists (random apps crashing continously) I can only think of logic board failure.
If you guys have any alternative suggestions on what could be wrong I'll be very happy to test them out.

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I guess one of the learning points I had from this experience was that sometimes all the different tests can't show all the defective parts. Just got to hunch it at times.