Alas, I also have suddenly started seeing the dreaded elem.c-923 error. I've been running Retrospect without problems for months and months, and I didn't make any changes near the time that this started. All of a sudden, I started finding that when I check my backup server in the morning, Retrospect will have died with a last gasp of "elem.c-923!"
The log doesn't show anything useful. It has the last successfully completed backup, then a blank line, then the "Internal consistency check failed" entry with no timestamp. So I can't tell if it's associated with the start of backing up another client, or something that happens while scanning, or what.
I'm running Retrospect 6.1.126 on Mac OS X 10.4.3 on a 400 MHz G3 iMac ("smoke" translucent body) with 384 MB RAM. It's acting as a dedicated network backup server, backing up via firewire to a Granite Digital hot-swappable drive enclosure into which I place IDE drives. Retrospect has 20 network clients registered, though four of them aren't turned on very often. Most of the clients are desktops backed up by a script that runs overnight but not during the day; a few are laptops backed up by a script that runs 24/7; and one is a server backed up during a specific interval in the early morning, after the desktop script is done.
I alternate between two backup sets, each one on a different 250 GB IDE drive that gets inserted into the drive enclosure. I've had the elem.c-923 with both backup sets.
Suggestions? Wisdom? Thanks!!