| Mixing 2 different ram quantities and different brands can lead to bad things happening like blue screens.  I would replace the old sticks with the new ones.  It'll be impossible to tell a difference between 2.5 and 2 GB so it doesn't matter anyway. 
				__________________"A Darwinian attacks his theory, seeking to find flaws. An ID believer defends his theory, seeking to conceal flaws."  -Roger Ebert
 |