Did you buy from Disney? If so, there also may be different restrictions for existing members adding on vs. new members buying in. (although reading Mr. Disney's post above mine, it sounds like they are letting add-ons be banked too)
All I can do is share my experience from 2 weeks ago, and you all can take it for what it is worth.
I just bought 200 BWV points with an August UY from Disney on Friday, June 9th. My guide told me that I would have to use the 200 '05-06 points by 7/31 or lose them. I posted about it at the other
DVC board and Tony Greenbanned, who also posts here, pm'd me to let me know that wasn't the case.
I called Monday, June 12th, to talk to MS about it and make my first reservations, after worrying all weekend about what to do with the 200 points. The first thing the MS representative said to me when she pulled up my account was "Do you want to bank those points? We always lift the banking restriction for new members?"
So, my guide told me the WRONG INFORMATION. MS will let NEW MEMBERS bank the points that come with their contract if they buy from Disney.