DBus is not Ubuntu-specific. You can find it in almost every distribution. If you accept generic DBus questions, then you must accept generic Python, C++, GTK, Qt questions as well.
One thing is asking questions about programming with tools really specific to Ubuntu (e.g. Unity) or about Ubuntu customizations (e.g. fortified source). A different thing is asking purely generic questions about stuff that is in he Ubuntu archives.
The reason why I do not want to see such questions is that very few people (perhaps nobody) is going to answer them here. The OP will have much more luck asking on StackOverflow and other sites.