I think it is a problem with the kernel but I'm not sure. If you can make it see all 4gb then I'll pay you.
this is what fdcservers said:
Answer: yeah. himem support is installed cause you can see 3GB. The 4GB is being hidden by the bios (it's a bios message on boot)
Question:Is there any possible way to get a motherboard to let me use all 4gbs. Would of been a waste of $$ if i cant
Answer:It's being used by the system to increase transfer speeds between the other 3 sticks and the main system hardware. You'll see a noticeable increase in response time because of it.'t even use it.