Problems with Sapphire Radeon X800

Hi, i have a pc composed from:

Power Supply Power supply: Chieftec 360 Watt
Motherboard: Epox 8hda3+ with the last bios
Cpu: Amd Athlon 64 3000+
Memory: 2x 512 Mb Corsair cmx512-3200c2pt
Primary hard disk: Western Digital Raptor 36 gb sata
Secondary Hard Disk: Western Digital Wd800jb pata (primary master on pata)
Cd-burner: Lite-on Ltr-24102b (secondary slave)
dvd-burner: Pioneer Dvr-106d (secondary master)
Video Card His Ati radeon 9800
Sound card: Creative Live!
O.s. Windows Xp Pro
The PC described here over works very well, but i tried to mount a Sapphire
Ati Radeon X800 Pro and when i boot my pc remains blocked with black screen.
I tried my new video card with other pc and work very well, i have changed
the power supply with an other (Thermaltake Purepower 480 watt) but the pc
remains always blocked in phase of ignition, I have tried to detach all the
fixed cards and hard disk , but it does not change nothing.
I have tried also to vary agp voices in the bios, but also without to obtain
no result here
The Sapphire Radeon x800 isn't compatibile with Epox 8hda3+ or i must
setting some particular voice in the bios?
Is there someone with a Sapphire Radeon x800 and a Epox 8hda3+ ?
Thanks to all