FC6 - Incorrect Memory size

["CC Chaman" <cchaman@xxxxxxxxx>]

Hi,

First post, so please forgive if this is in the wrong board.

I've installed Zod on a Dell 2950 with 8 GB Ram. The 2.6.18 kernel only reports 4GB, so I decided to do an "yum upgrade" ... excpet now with the 
2.6.19 kernel I only have 3.2 GB

Here's the top output:
Mem:   3368804k total,   743888k used,  2624916k free,    43428k buffers
Swap:  2031608k total,        0k used,  2031608k free,   429312k cached


Here's the fun part...when I boot with Xen - Ram is reported correctly?

Any help would be appreciated!

( I did try setting kernel parameter mem=8192M ... does not work)

Thankx

CC-