Notes 7 error message after pressing send

Hello everyone I’m a notes admin newbie but there is this one problem I am receiving with users. The user can log into their notes account, go into mail, and create a email but once they hit send it gives this notes error message that says:

(Lotus Notes Error Notification

An error has occurred in a Lotus Notes Application.

Data about the error is being collected for your company’s help desk for use in error analysis.

The Lotus application will close when data collection is complete. Please wait).

The only way to get ride of the message is to do a ctrl+alt+del or disconnect the users citric connection. We are using a Citrix environment and Notes 6.5 templates but the Domino Server itself is notes 7.01. I was thinking maybe it may be a problem with the template versions. But I also say where users who have the spell check enabled get this probhttp://www-10.lotus.com/ldd/nd6forum.nsf/Main%20Topic?OpenForm&Login&Seq=1

Postlem as well. Any advise would help alot. My next choice is to redo our Domino server.