[Brian]

Moniker, I'm really sorry for the trouble this is causing! It looks like we've gotten three reports of a problem like this; all within the last two months. We've never managed to reproduce the problem, though, so we're not sure what causes it.

It looks like two of the customers that reported the problem were on laptops; the third didn't respond to our request for more info. Everyone seems to be running 10.6. There's some speculation that the problem is related to undoing actions that were originally performed using the new multi-touch gestures that were added recently, but that's purely speculation.

Does any of this line up with your experience? If so, can you let me know if the problem persists if you start working in a new OmniGraffle document, or does it seem to be document-specific?

We're still trying to nail down exactly what folks are seeing, so any info/steps/sample documents you can provide would be very helpful.