asterisk users - Jan 2005 - Box unstable after loading zaptel drivers for X100P

Hi list!

I have been experiencing a lot of mystical hangs on my box. At first I 
suspected bad memory or motherboard but I found out that the mystical 
hangs disappear when I do not load the drivers for my x100p.

The box will only hang under high load (copy operations with 30Mb/sec to a 
raid array in the box for example). With little or no load the box will 
stay up forever. (The imposed load is not asterisk related and the box 
will hang even when the X100P is not in use).

This is the hardware setup: Asus A7V600 mainboard, Athlon XP2500, 1Gb of 
mem, one 3Ware 7500-8, one X100P. There are no other add on cards in the 
system and I'm using the onboard LAN. All unused hardware is disabled in 
the BIOS and no support for that hardware is compiled in the kernel (I 
disabled second serial port, parallell port, USB ports, FireWire ports). 
The motherboard setting for IRQ's is set to APIC (instead of PIC) and APIC 
as well as IOAPIC are compiled in the kernel. ACPI is enabled in the 
kernel but without any options.

I am using Asterisk 1.0.3 with zaptel 1.0.3 on Gentoo with kernel 
gentoo-dev-sources 2.6.9-r13 (I have been experiencing this behaviour 
already since kernel 2.6.8 but didn't know why).

This is the output of
root # cat /proc/interrupts
            CPU0
   0:   46440826    IO-APIC-edge  timer
   1:        722    IO-APIC-edge  i8042
   4:      41804    IO-APIC-edge  serial
   8:          2    IO-APIC-edge  rtc
   9:          0   IO-APIC-level  acpi
  12:         66    IO-APIC-edge  i8042
  15:         24    IO-APIC-edge  ide1
  16:    5174982   IO-APIC-level  3ware Storage Controller
  18:  349692696   IO-APIC-level  SysKonnect SK-98xx, eth1
  19:     421707   IO-APIC-level  wcfxo
NMI:          0
LOC:   46448330
ERR:          0
MIS:         86

The box is rock solid when I unload wxfxo and zaptel, no matter what load 
i put on it I cannot bring it down. When loading zaptel and wcfxo the box 
will completely freeze when the load increases.

Ideas anyone?

Thanks!!