Let's keep track of these in one place. Provide as much detail as possible so that others and maybe Capcom can also cause them to happen and thus maybe fix them. Videos (with descriptions) showing the problem are also excellent.
http://zachd.com/mvc2 : My giant archive of fighting game videos, centered around MvC2.
"If you don't feel like killing yourself every time you lose you will never be good. Apologyman is going to be a monster someday as long as he keeps staying miserable." --Brightside6382