Major bugs
Game slows down and freezes
This is due to some imperfections in event handling. What happens is that the game core spends more time displaying things than processing events. Therefore there's a growing time gap between what's displayed and what's being calculated internally, at an event level. And the situation gets worse and worse as the display gets slower since the engine has to anticipate many frames. So the game chokes to death... I'm trying to find a compromise between real-time constraints and performance issues.
Still, keep in mind that with "recent" computers, running at more than 1GHz, there's almost no chance that you ever hear about this bug. I used to run (and develop BTW) U61 on a K6-200, and I had no problems with it. However, you need to know that it "can" happen, especially if your machine is old and/or its CPU is heavily used by some other programs.
Minor bugs
Win32 event dispatcher received WM_QUIT
You might get this message if you run U61 in windowed mode under Windows and close the application by clicking the standard "cross" which is in the top-right corner of the window.
Unable to type dots and other weird characters
Due to some limitations in key handling in ClanLib, you might get trouble trying to type characters such as "." or "-". This is very annoying since you need them to type ip addresses and/or machine names. Still, there's a workaround for ".", which is usually the most annoying character: simply press the space bar on your keyboard and it will enter "." instead of " " if you are editing a server name.
The numpad keys won't work
Again, this is due to the fact that ClanLib is still under heavy developpement. I'll try and do my best so that this bug is fixed some day, since it is very important for U61 that all the keys work correctly.