Weird problem with NMM that occurs every day. If I load it up for the first time in any given day NMM gives me all accurate up to date information on what the most recent versions of all mods are.... if I close it and then load it up again that same day everytime after it quotes information at least 3-4 days old and I can't seem to fix the problem.
There's a green arrow on the right hand side that goes in a circle. That's refresh. It won't stop it from happening, but it'll give you the right information.