I know this is just about a year old, we identified this same issue, little sad if you ask me that PTC makes Creo so dependant on windchill and makes Creo work so well with family tables but yet windchill cant deal with family tables properly.....
however we did find a solution, we have been working with a developer for a differerent issue and they provided us with a Library wizard tool that takes family table parts and strips the generics out and checks the generics into windchill. Best solution to the problem so far, www.dandq.ca is the developer's website, program we have been using is Control's pro studio. I would email them for a demo