I am wanting to say you have ram similar to me, enough to work, but you get random bluescreens, it sounds as if it's starting to corrupt system files, you may want to get that test performed ASAP, and post the results.... That, or your file system is really screwed, so it at all possible, at least make a backup of important files so they don't become corrupt if corruption is starting to take place.
Also, can you tell us your RAM configuration? If you have multiple sticks, testing each stick separate, and in combination helps detect if there is a bad stick as some sticks only error in combo with other sticks.