When publishing updates through scup catalogs, i have no issues with Flash or Reader, however Acrobat updates always get stuck installing, and sometimes prompt users without admin rights, that another account needs to display a message.
When clicking this message, the user account gets switched out and a gray screen with a message says acrobat can't continue installing until outlook/reader/IE/etc are closed. However even if these are closed, the installer will not continue, and sometimes when rebooting the installer will stick as well during the windows loading process.
This happens on windows xp, vista, 7 and 8