Versions: Win7 & Movie Maker 2012 (build 16.4.3528.0331).

I've made about one dozen movies that I've used slide transitions (Animations) in the past, using various transitions.  Worked (past tense) wonderfully.  However, now whenever I try to put a transition in, it still occurs but it goes by so quick that you can't tell what the transition is: diagonals, disolves, patterns & shapes, etc.  The default transition length is 1.5 sec & I've tried pushing this up to 2 or 3 sec to no avail.  They appear to be about 1/8 or at best, ¼ second long.  I've uninstalled all of essentials & reinstalled Movie Maker but that hasn't fixed it.  Since I'm still using the same PC, something else must have been corrupted but I'm not sure where to look.  Can you point me in the right direction as to what dll or codec I should look to update?