I am using this site from more than a year and this is the best discussion form i know. Moreover, the features of this are itself good. But as suggestion for some change i can suggest that there must be some option of "Notification by Email", not only when u are starting a topic, but also when u are randomly replying to some topic. This happened to me a lot of times that i replied to some questions and then waited for expert comments.. but in some time if forgot which topics to check again.
Hope this will help you to improve and users to get better service.
This is a common request and the answer is, unfortunately, always the same: UBB doesn't support arbitrary email notifications. If you forget to set email notification on, you'll have to delete the topic and create a new one with the flag set.
This will be corrected in the new forum software, although its deployment isn't anytime soon...