Might I suggest adding the below instead of swapping it out?

-d

>--- linux-2.4.18-pre1/drivers/scsi/sd.c	Fri Nov  9 14:05:06 2001
>+++ linux-2.4.18-pre1-p3/drivers/scsi/sd.c	Mon Jan 28 14:46:11 2002
>@@ -302,7 +302,7 @@
> 
> 	dpnt = &rscsi_disks[dev];
> 	if (devm >= (sd_template.dev_max << 4) ||
>-	    !dpnt ||
>+	    !dpnt->device ||
> 	    !dpnt->device->online ||
>  	    block + SCpnt->request.nr_sectors > sd[devm].nr_sects) {
> 		SCSI_LOG_HLQUEUE(2, printk("Finishing %ld sectors\n", SCpnt->request.nr_sectors));
>