Dell 1501 incorrect VRAM shown in profiler

Okay i've had OSX 10.5.8 running on my dell 1501 for some time now but one thing that has bothered me i cant figure out why when i goto "system profiler" it only shows that i have 48mb of VRAM when it should be 128.

After the install i used Callisto.kext and CallistoHAL.kext to get the correct display resolution. Does anyone have any idea on how to fix this?

I've searched google and all the forums i know of until my fingers are raw with no useful results.

here are the specs
CPU: AMD Turion 64 X2 TL-53
MOBO: ATI Radeon RS480
RAM: 2048 MB, DDR2-533 SDRAM,
CARD VIDEO: ATI Mobility Radeon Xpress 1150 - 128 MB 256 MB Hypermemory (ATI RD580)
SCREEN: 15.4 Zoll 16:10, 1280x800 Pixel, WXGA TrueLife TFT pantalla,
HD:250gb 7200rpm Samsung
SOUND CARD: ATI SB600 HD Audio (Sigmatel 9200)
INTERFACES: ExpressCard, microf�no, auricular, 4x USB 2.0, VGA-out, Kensington Lock, LAN, modem
WIFI & LAN: Dell Wireless 1390 802.11g, 10/100 LAN, 56K modem
DVD: DVD +/-R (DL) TSST TS-L632D
OTHER: 3in1 cardreader

http://i254.photobucket.com/albums/h...shots/48mb.png

Hi Did you find an answer? and wuld this be causing choppy video playback and blank black screen in vlc?
Thanks