Adaptec 79xx > 1GB I/O errors

[Michael Madore]

I have been getting the following I/O errors while stress testing a 
system with the latest Adaptec 79xx driver (1.3.0BETA2):

Jan 14 09:29:13 asl200 kernel: SCSI disk error : host 0 channel 0 id 0 
lun 0 return code = 8000002
Jan 14 09:29:13 asl200 kernel: Info fld=0x86c552, Deferred sd08:02: 
sense key Hardware Error
Jan 14 09:29:13 asl200 kernel: Additional sense indicates Internal 
target failure
Jan 14 09:29:13 asl200 kernel:  I/O error: dev 08:02, sector 487312

Jan 14 10:36:37 asl200 kernel: (scsi0:A:0:0): Locking max tag count at 64

This is with kernel 2.4.19 + 2.4.19rc5aa1.  I have tested with several 
different Ultra 320 drives, with the same result.  If I remove memory 
from the machine so that it only has 1GB, then everything is solid as a 
rock.  If I plug a zero channel raid controller into the same system 
(dpt_i2o), then I don't get any I/O error regardless of the amount of 
RAM.  Any thoughts?

Mike