There is one thing I am missing in this bugtracker, something like an information text that appears if you want to submit an issue.
All the time when users report game crashs or problems the devs are asking the same questions. Are you using mods, please add your rpt, please add your dxdiag, ect.
This costs time, it would be more easy to just add a message above the submit form containing: "If you game crashs please add your dxdiag-file and your latest rpt-file to this ticket" (also links to websites with help how to get the files).
And something like an select box where users can select whether they are using custom content. (should be possible with the Mantis system)
Just an idea to make your work easier.