I wasn't sure if the bug system or the forum system is the appropriate place to file bugs
The sourceforge bug tracker is the preferred place to report a simple bug such as this. I saw your report on Friday, and would have committed it immediately, but wanted to check with the programming lead, tzlaine, first, since I don't know much about graphviz or the particulars of the code that was changed.
If a "bug" is really a more in-depth issue that ventures into design issues, then a forum discussion is probably necessary.
Where can I find the discussions on the most active developing areas of the codebase in the short term.
Most coding / implementation discussions are done privately by email, though similar to the above note, if something requires design input, then it will likely be discussed on the forums. I've been doing some sidepanel UI work recently, and there's a few threads on the Graphics forum related to what I'm doing, but not so much about how I'm doing it.
That said, if you have any questions about how something in the codebase works, feel free to post in the programming forum or to email me, and I might be able to help.
Also, if you want something to work on, but aren't sure what needs doing, I can suggest a few things...