The only solution at the moment:
1. Uninstall Captivate
2. Reinstall Captivate 6.0.1
DON't upgrade to 6.1, because then it doesn't work anymore.
by the way, this will only work for the 32-bit version. The 64-bit version will not work with Office2013 (not even version 6.0.1).
Hope this can help other people with the same problems.