Why only works with Xen Kernel ?

[Newton]

Dear Friends :
I have an ASUS M2N-MX (sound and ethernet onboard), 4200 Athlon 64 X2, 2 
Gb (DDR2), 250Gb SATA-II, 7300LE XFX (videocard) and, I'm trying many 
Linux distributions, including Fedora, since 6 version (with this 
machine - I knew Fedora, since first one) ! I'm very disappointed, cause 
it only works with Xen Kernel    (2.6.20-2925.13.fc7xen)and, I can't use 
my videocard acceleration, no desktop effects and so on ! Also 
sometimes, I have sound at one speaker and, eventually, at both ! When I 
try to boot with " normal " kernel (2.6.22.1-41.fc7) , hangs at starting 
firewall or, when looking for hardware ! Is there a way to solve this 
situation ? When I tried another distributions, I had another errors, 
including frequency monitor (???), no sound, and so on... Debian Etch 
(4.0), was the easiest install (almost all recognized) but extremely 
unstable ! I lost how many times, I had to reset this machine !
Sincerely,
Newton - Brazil