I've noticed some odd behavior like this with old docs and stuff. The best fix I've found for it is:
Rather than double-clicking the icon to open something, either open the application you want to use first, then use the OPEN command and open the old file. Then save it. Or, drag the icon you want to open to the icon of the app you want to use to open it (either in a finder window/desktop, or in the Dock) and drop it. The system will force it open with the new app, but be sure to save it. Once I did that, it always opens within OS X, if it can.