When I click the help button "?" in the Custom Settings dialogs for some of the codecs listed within Render As, the mouse pointer turns into a context sensitive help icon (arrow with "?") but no help pops up when dialog items are clicked. For example, for Mainconcept AVC and Sony AVC the Custom Dialog help system is broken. I think I saw some others that are broken. Panasonic seems to be okay.
Can anyone confirm? Hope this is being worked on.