That's a great tip thanks Lynne, I did already have the template name thingy enabled but hadn't looked at the source code :s. Will most very useful for future modifications, however didn't help in this case, have found where it is set but theew doesn't seem to be a template directly associated with it, all it has is:
<!-- sub-forum list -->
Don't think this is a template in itself, could be wrong tho so maybe it's a sub-section of forumdisplay.php??
--------------- Added [DATE]1235173012[/DATE] at [TIME]1235173012[/TIME] ---------------
W00t, found it, thanks for your help Lynne

.