Hi Tom,
It is a bit of a workaround but what I do in the same situation is to create a new minor version and then delete the rules one by one for troubleshooting purposes and then copy and paste them back into the new version from the most previous version once I have eliminated them as the source of the problem. Once I have found the problem, I usually modify my original version and then delete that newest version in case there was something that I forgot to paste back in.
Cheers,
Pete