if you press "help" after heving chosen a helper application you cannot remove or edit or add a new helper application - the whole menu for editing/adding/removing simply disappears!
WFM: Win2k/2002082704. Changing summary.
It happens when the helper app has a long file path.. bug 133627 is general pref bug. bug 138680 is helper pref bug. *** This bug has been marked as a duplicate of 138680 ***