Stephen, I’ve done many scans from the ScanSnap to DT Pro and have only seen scan failures when a sheet didn’t feed properly. That seems most likely to happen with flimsy paper. The error message is produced by the ScanSnap, not DT Pro.
Nope, I’ve had those (flimsy carbon copies, etc) but this is different. No error message from ScanSnap software, just a “Failed” in the DTPro log… and no document!
Absolutely 100% repeatable. I just quit out of DTP and restarted it, just to prove it to myself. First scan fails. Rescanning the exact same document (pulling it out of the output tray, dropping it back in the input slot) is successful.
The PDF functions of Mac OS X contain some bugs that lead to these failed imports. Same is with exports from Pages that sometimes fail, and nobody knows why. We’ll add some code to a future version of DEVONthink that will do two or three retries before giving up.