I've spent considerable time looking into this, but have drawn a blank. It appears that your capture action was simply "stuck" opening the archive. But I can't reproduce it here, and I can't imagine any reason for this to happen.
To help diagnose the problem, I've prepared a test version of QRecall I'd like you (and anyone else who's interested) to download and try. It's identical to the 1.0.0(55) release except that it logs detailed messages to the log file as the repository files are opened and closed. Hopefully, this will give me enough information to figure out what's going on.
Download:
QRecall 1.0.0b(55)c To install
1) Trash (or set aside) QRecall 1.0.0b(55)
2) Copy 1.0.0b(55)c to the previous location of 1.0.0b(55)
3) Launch 1.0.0b(55)c
You will need to reauthorize it. Afterwards, perform a number of captures. If the action still get stuck at "Opening archive", cancel the action and forward a copy of the log file to me. (You're welcome to send me log files even if it doesn't get stuck.)