I have an old PackardBell Mz36 (easynote) running on windows vista. Trying to upgrade it to 2 Gigs of memory (currently running on 1 Gig). But somehow every time i try put in another memory (1G), I have a Checksum error. Ive tried replacing Cmos Battery, Inter changing memory possitions. And even updating the bios (with the update from Packardbell support). but still the same. Can any one help me with this problem?