I often use the "filter these messages" box in the top tool bar.
Many times the message I am seeking pops up quickly, and I'd like to then GO TO that message. As it is now, if I try to stop the search before it completes, it wipes out the search results.
Roland Tanglao with Mozilla support says: "i don't think there is a way to stop the filter process early. "
I'd like to suggest Mozilla consider a "new feature" to allow user to stop the filter process and open the desired email, when the info needed is found, w/o having to wait for the entire search to be completed.