The problem with using the forum is that you have no way to capture the relationship between bugs, releases, browser, steps to repeat the bug...etc.
I wouldn't go so far as adding a bug tracker at this point. eGroupware is a disaster (IMHO) in their attempt to add so many different modules without having the resources to implement them properly or maintain them. SugarCRM, to some extent, is the same: they have a lot of modules but a lot of them don't work particularly well (e.g. the email module, even though it was recently revised; the bug tracker, which is feature poor vs the other solutions out there).
I would concentrate on perfecting the other modules first. I'm looking for a replacement for our customized version of Web2Project, a fork of dotProject, which is too confusing for users. I also created an internal fork of ProjectPier, which was never deployed because I just find that that platform (even the current ActiveCollab) is too lightweight for project management with regard to the user interface (how information is accessed, presented, etc.). Clearly, OpenGoo has made quite the progress since I last looked at it (when it was first forked).
Contact me by email if you need administrative help to setup a bug tracker.