We don't support Konqueror, and probably won't in the near future just because of time, and the level of usage for konqueror (very low). Opera at least on windows I haven't seen any issues besides the one reported about the new left ad stuff. Products are coded for the majority, always, sometimes that means the less popular clients aren't completely supported. It's not intentional, just only so much time in a day, and we support the most popular browsers first (which makes clear sense). The forums like any other web application read in cgi variables to get the browser type, and well if you start spoofing it etc then it won't get read properly (absolutely nothing can be done about that).
Hope that explains.
If you're curious the forum stats for april for browsers are:
MSIE: 89%
Netscape: 8%
Opera: 3%
AOL: 0%
Konqueror: 0%
Of course the 0% are relative to the rest.