Grub Problem on SATA Raid

[M.e.M.O.]

hi ,

i have been using Fedora With SATA raid on VT8237 Via South Brigde without much problems. but when Grub was gone, due to Reinstall of Win , i wasnt be able to install it without Reinstalling full FC6 . There was an error like " Grub cannot install on Device Mapper's devices. "

And while installing FC6, i had to use " Force LBA32 " , otherwise it wouldn't boot.

One of my Rams and Mobo gone . i switched my Mobo with nVidia chipset one, and using the same config. 2x SATA Seagate drives , on RAID 0 (Stripe) config , i have set up Win , and its running without problems.

The Problem is: i'm setting up Fedora , but it directly boots into WinXP . i can't see Grub screen . i both tried to use LBA32 , and normal way, both didn't work. 3 times i installed FC& but there is no way to see grub boot loader in action.
is there a way to fix it? and also if you know way to re-install grub without reinstalling FC , it's also wellcome.

ps: as a side note, while installing FC6 , i see some warning messages in background , like : " Via and nVidia formats found, using nVidia! " . what does it mean?

[M.e.M.O.]

no ideas?