Please describe the problem:
When viewing a message either inline in the main view or in a separate
window, it is possible to find the first result of a search in the
message, and it is possible to see the total number of matches, and the
previous button lets you cycle through the matches backwards, but the
next button doesn't cycle forward through search results. Instead it has
no effect.

Steps to reproduce:
1. View a message where a word in the message body is repeated multiple times
2. Press Ctrl-Shift-F and search for the repeated word
3. Press the "Next" and "Previous" button multiple times to step through the matches


Actual results:
Backward stepping works, forward stepping stops at the first match.

Expected results:
Forward stepping should step through all matches

Does this happen every time?
Yes

Other information:
This bug was originally reported by Trevor Caira at http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=428146