usb - deleting (irq)

FreeBSD 4.5
i installed my sound drivers (which are onboard) with the following lines in my kernel
device pcm
options PNPBIOS

then cd /dev
sh MAKEDEV snd0

output from cat /dev/sndstat show the devicedriver (correct one)

ok this works nice
untill i enter my kde and want to play a song. There i see in the terminal ***WARNING **: oss_open(): Failed to open audio device (/dev/dsp): Device busy (i have my acces (xwr)to /dev/dsp and its links)
now, i thought it could be it's using the same irq as an other device and i did #dmesg pcm and say it is using the same irq (11) as USB A. That pissed me off i don't need USB but it's all onboard unfortunately so i tried to rebuild my kernel without the USB declaration in it but yet every time i reboot with new kernels, the USB is still present!. How can i really get those USB lines out of my kernel or perhaps even better; how can i chance irq for the devices?

i hope someone might know the answer because we've been looking on the problem with 3 people.

ow yeah, also tried it without the PNPBIOS option

thougth somebody would like to know how i'm doing with my sound?
wel, still nothing but i learned again some important things
like you cannot change you're irq's in freebsd so i changed them in BIOS, deleted usb irq, changed sound irq, switched sound irq with screen, ... nothing helped.

still getting the same error msg which basicly says "request interrupt timeout, channel is dead"
and after that, the output of /dev/dsp is
"Device busy"

i tried almost everything in my kernel from option PNPBIOS (on/off),
device pcm
device pcm0

strange thing is, he finds the correct device when is cat /dev/sndstat

is there anybody who has any idea on how this could be solved?