I've had all the problems with Mavericks and Skype, and it seems like each update has fixed one thing here and there, but I'm left with a huge issue (because I use it for business).
If I call one person - video works for both.
If I try to add a 3rd person, through video, the first person I am on with loses video from both parties and I can't see them either. I can see the 3rd person though.
Yes, I have a premium account and have been using skype this way for a while to record calls like this.