I've just spent a considerable amount of time troubleshooting a problem with interactions to find out that there was no problem at all.
Basically I had a "0px height initial appearance" action which stopped working suddenly and unexpectedly. After trying everything I could think off to troubleshoot I removed the interaction from one of the objects that had it and then assigned it to them again, voila it works... only for that object though. Repeating the process for all the others fixed them too.
I have no idea why this happened but needless to say that it has been the cause of a lot of headaches!
Has anyone else experienced this?