RAM error

I have a mid 2009 MBP: 160 GB HD, 2.26 GHz Core 2 Duo, 4 GB DDR3 RAM.

The Mac has been taking spells where it doesn't want to wake from sleep. I've been getting this problem for about a month and a half and it's finally on my last nerve. Sometimes the System Profiler shows 4 GB (2x2) and sometimes it only shows 2 (2 in Bank 0 and empty in Bank 1). Does that mean my stick in Bank 1 is faulty and needs replaced? Would a reinstallation of Snow Leopard fix the problem? Please reassure me that it's not the logic board with the problem

 

I've ran the Hardware test already. It shows everything as normal. I'm a recent convert as of '09 (definitely for life though). Coming from a life of Windows based computers I want to blame a virus, spyware, etc. I don't imagine that's the problem, knowing that Macs have virtually no problems in that area. I just need to get my MBP back to good health asap

 

I got the MBP in July '09. It was a gift and apparently Apple Care was not purchased with it (bummer, I know).
I've ran the hardware test and it was negative. I've switched the sticks already, to no avail.
The problem is easily replicated. For instance, I can be using it as I am now, then put the computer to sleep and close the lid. Then I can reopen it a few minutes later and the indicator light goes bright but the screen stays black. Nothing shows that the computer is awake. The nearest Apple store is two hours away but there is a MacConnection an hour away. I might have to go see them sometime this week and get their opinion (hopefully at a decent price, if not free)

 

Just saw your reply. Just looked at system profiler and it shows 4 GB RAM now. It likes to switch between 2/4 GB. I had to manually restart via power button because it was doing its 'refusing to wake from sleep' mode.