2.5.1-pre8: lockups whem mounting scsi cdrom

[Carl Scarfoglio]

HW: MB Asus A7V, 256MB Ram, Athlon 800 MHz,four HD attache to standard
ATA and ATA-100 Promise controller, 1 Realtek 8029 ethernet adapter,
Adaptec 2904 (AIC 7850), 1 scsi CD-writer (Waitec. i.e. Philips 2200 or
so), Teac scsi CD-ROM, 1 Mustek A3 plugged to external scsi connector.
The Adaptec has Irq 11 exclusilively.
SW: SuSE 6.3 with some changes, gcc 2.9.3.

I am running 2.5.1-pre8. I cannot mount data CD. When I execute the
mount command, on any drive, a hard lockup follows. No messages from the
mount command, no noise from the drives.
The PC hangs solid: keyboard and mouse are dead, no telnet access, when
in X the session is dead. I must flip the power switch.

But I can write CD's with cdrecord and play audio CD's!!

Kernel 2.5.0 does not have this problem.

TIA

Carlo Scarfoglio