Both use years show up in your same account on-line. However, you cannot use both contracts to make one continuous reservation (absent transferring points).instead you need to make one reservation for part of trip with one use year and another reservation for rest of the trip with the other and then call or email MS to link the two reservations, Linking results in not having to change rooms.
As to problems with My Disney Experience, I am unaware of what you have seen but having two contracts is undoubtedly not the only thing that is being reported since I have seen a number of problems reported by persons with just one use year. I assume eventually those will be resolved. Moreover, if there are problems I guess I will soon be finding out. We have a trip coming up in November using two use years. Thus far I have not had any problems at least on-line since I put both reservations in the My Disney Experience, have made made dining ressies, done FP+ for all days and received the bracelets. Just don't know yet what problems will occur once we get there.
In other words, thus far I have seen no particular problems with the
DVC site or My Disney Experience resulting from having two use years, but still waiting to see if anything goes wrong when I get to WDW.
