This happened to me before, and just recently with the update from 0.33.2 to 0.33.3:
When I start AltBinz it checks its validity, then I shortly see the popup that informs me about the new version avaiable, only for that window to lose focus. Then I see only the normal AltBinz Window, but I cannot do anything with it, as I would have to click OK on the notifier-window -- yet for it being in background it's kind of a hard thing to do.
Sometimes I am able to get to that window via minimizing/maximising the altBinz window, yet the best solution is upgrading AltBinz altogether, which I would have done at some time anyway -- yet it's kind of annoying being forced to upgrade when I just want to download something with altBinz and being unable to do so.
My OS: WinXP SP3, all updates.