Error messages from SCSI (sym and ahc)

[Juergen Dankoweit]

Hello to the list,

on several test machines in our company we get these error messages from
the SCSI-HBA drivers:
(noperiph:sym1:-1:-1): SCSI Bus reset detected
(pass1:sym1:0:2:0): phase change 2-3 16 at bc310b68 resid=10
(pass1:sym1:0:2:0): phase change 2-1 16 at bc310b68 resid=6

Changing that LSI adaptor to an Adaptec 29160N the following error
messages are shown:
(pass0:ahc0:0:2:0) No or incomplete CDB sent to device
ahc: Issued Channel A Bus reset. 1 SCBs aborted

pass1 (at sym) and pass0 (at ahc) are an SCSI-DVD-RAM (Panasonic
LF-D201). The device is unusable.
But the funny things are: We installed FreeBSD from THIS device...
and FreeBSD 5.5 does not show those messages...

Information about the used system:
Siemens-Fujitsu Primergy C200, LSI 53C1010 onboard, dual CPU (1,4GHz),
3GB RAM, FreeBSD 6.2 (current source code).
The SCSI bus was tested with special SCSI test hardware is Ok.

What does the system wants to say to me?

Many thanks for the answers

J. Dankoweit