suspend on ASUS p4p8x

I have 6-CURRENT running on a P4 machine with
an ASUS P4P8X motherboard.   Any time I try 
to suspend the machine (acpiconf -s 3), 
it resumes fine, but then displays the following:

ad0: WARNING - READ_DMA interrupt was seen but timeout fired LBA=91692863
ad0: WARNING - READ_DMA interrupt was seen but taskqueue stalled LBA=156244063


...and hangs after 5-6 seconds.

Unfortunately I could not get a crash dump (I don't know why,
I've followed the handbook instructions to the letter;
and typing "panic" at the debugger prompt doesn't do anything).

panic: vwakeup: neg numoutput
KDB: enter: panic
[thread 100000]
Stopped at 	kdb_enter+0x2b: nop
db> trace
kdb_enter(c05a7fba) at kdb_enter+0x2b
panic(c05ac743,cbbe6008,d3f75c44,c04d379a,cbbe6008) at panic+0xbb
vwakeup(cbbe6008) at vwakeup+0x5f
bufdone(cbbe6008) at bufdone+0xf6
bufdonebio(cbbe6008) at bufdonebio+0x3f
biodone(cbbe6008,c1a037bc,c1a037bc,c156f400,d3f75c88) at biodone+0x86
g_dev_done(c1a037bc) at g_dev_done+0x5b
biodone(c1a037bc,c171121c,d3f75cac,c042a072,c171121c) at biodone+0x86
ad_done(c171121c) at ad_done+0x2d
ata_completed(c171121c,0,c05a80dc) at ata_completed+0x3ee
ata_timeout(c171121c) at ata_timeout+0xf6
softclock(0) at softclock+0x217
ithread_loop(c1573500,d3f75d48) at ithread_loop+0x155
fork_exit(c04793e8,c1573500,d3f75d48) at fork_exit+0x75
fork_trampoline() at fork_trampoline+0x8
--- trap 0x1, eip = 0, esp = 0xd3f75d7c, ebp = 0 ---

The kernel config is at http://www.math.uic.edu/~vladimir/TINY,
acpidump -t -d output at 
http://www.math.uic.edu/~vladimir/asus.asl, and verbose
boot at http://www.math.uic.edu/~vladimir/boot-v
The motherboard has an up-to-date bios.

I'll be happy to debug this further; but otherwise not
a big deal.

Thanks,
--
Vladimir