C2 connected to Sun V210: scsi messages

hello all,
every time i reboot the host, i got these messages:
WARNING: /pci@1c,600000/scsi@2,1 (glm1):
Connected command timeout for Target 5.0
WARNING: /pci@1c,600000/scsi@2,1 (glm1):
Target 5 reducing sync. transfer rate
WARNING: /pci@1c,600000/scsi@2,1 (glm1):
got SCSI bus reset

puis 1mn plus tard:
WARNING: /pci@1c,600000/scsi@2,1 (glm1):
Connected command timeout for Target 5.0
WARNING: /pci@1c,600000/scsi@2,1 (glm1):
Target 5 reverting to async. mode
WARNING: /pci@1c,600000/scsi@2,1 (glm1):
got SCSI bus reset

does it mean there is a problem? or is it normal? how can i assure that
the scsi speed is optimum?

thanks in advance,

gerard