When you install are you doing a custom partition or are you letting Mandrake do the partition setup. With todays ram it is no longer necessary to double your ram for swap, a swap of 250 - 300 megs will do fine for most applications.
your geforce card, is that an ultra modern card ? or what.
Have you checked that is compatible on mandrake / mandriva's HCL
http://www1.mandrivalinux.com/en/hardware.php3
floppy