Instant Scan not working on one client?

[j.a.duke]

I've got one client which the server isn't using Instant Scan for backup.

 

This just started after the 7PM backup of the client last night.  Backups were running in 15-20 minutes with ISA on, now take at least 30 minutes, likely more.

 

Retrospect 10.5.0 (145) on a Mac Mini quad-core i7 running Mac OS X 10.7.5.

 

Instant Scan is enabled in the client (Mac OS X Server 10.6.8 on a 2006 xServe).  RetroISA process is happily chewing up CPU cycles there as well.

 

"Using Instant Scan" is missing from the start of the backup log for this client.

 

It is present on backups of other clients.

 

Client was at 10.2 something earlier, so I upgraded to 10.5 client.  I've disabled & enabled Instant Scan on the client side. 

 

I don't see anything on the forums about this problem or how to troubleshoot it.

 

This server was restarted last Friday, early morning.

 

Any suggestions?  Short of a restart (which is difficult for this server), anything else to try?

 

Thanks.

 

Cheers,

Jon