MSI K8N Neo4 Platinum and nvidia 250 GTS

Hi,

I'm trying to install an NVIDIA GTS250 on this motherboard but the PC
stalls during startup (hangs on memory detection failure). Using the
6800 graphic card there is no issue but when installing the new card,
the PC stalls (not even able to enter BIOS).
PC charateristics:
> Mainboard : MSI K8N Neo4/SLI (MS-7100)
> Chipset : nVidia nForce4
> Physical Memory : 2048 MB DDR-SDRAM
> Video Card : NVIDIA GeForce 6800
> Hard Disk : ST3500630AS (500 GB)
> Hard Disk : ST3500630AS (500 GB)
> DVD-Rom Drive : PIONEER DVD RW DVR-107D
> DVD-Rom Drive : SONY DVD RW DW-D22A
> PSU Coolermaster 700W
> Bios : Phoenix Technologies, LTD Version : 6.00 PG Date : 17 february
2005

Is this graphic card compatible with this motherboard?

Thanks in advance,
Bart