One thing me and my buddy would do is after a FP or a herioc where we grouped with someone else we would degroup back to solo and then regroup with each other. This seemed to fix it for us. We just had to remember to do this.
One thing we have had a problem with is not being able to see if the other is losing health. The character bar on the side would constantly show full health but if you actually targeted your partner you would see he was almost dead. Relogging helped with this but it is annoying when one of us is always playing a helaer and has to relog to be able to make sure our partner is not getting killed.
But these thing only happend when we were in a group and didn't degroup and then regroup afterwards.
And Mav thank you for the answer to my question