I always use the xfce4-terminal with all menu-shortcuts disabled so I don't get problems with shortcuts of terminal-apps. I have a terminal-app which uses th F1 key but the xfce4-terminal always catches it and tries to open the online-help. If I remember correctly this bug occurs first with the big xfce4-terminal-update 0.6.0 (sorry for reporting so late)
Read about menu accelerators in the manual.