Ok, is a cdrom problem, re-burned and now work!

Testing in progress:

x2600xt work good, without 3d (is normal)
x1950gt work good with 3d
x1900gt (mac flashed) not work, white screen
hd6450 not work, black screen

There is a strange thing: MorphOs boot only with original geforce installed (any slot), with only the x86 radeon the cdrom not start loading.