This appears to be a race condition bug. Just out of curiosity, are you running QRecall on a single or multi-processor Mac?
I think I've resolved the problem. If you want to experiment, I've uploaded an inter-release build:
http://www.qrecall.com/release/QRecall_1.0.0b42.i.dmg. Warning: This has a bunch of other untested changes, so try it at your own risk.
To install the new version: (1) download the disk image. (2) Trash (but don't delete) your currently installed version of QRecall. (3) Copy the new version into its place. (4) Launch the new version and reauthorize it. (5) Delete the old version.
Bruce Giles wrote:I re-launched QRecall and tried to open the same archive again, and this time it opened without any problems. I did not get any warnings about needing to reindex or repair the archive, so presumably it was unaffected by the crash.
When browsing, QRecall opens the archive in read-only mode. So browsing can't alter or damage the archive in any way, no matter what happens to the application.
(Well, that's not entirely true. You can change the archive settings while browsing, but the worst that would happen is the archive would lose its custom settings.)