ALL antivirus software eventually has a false-positive problem with something. Some more than others. How much you know about it and how much people whine is directly proportional to the popularity of the app/service/etc. that it ends up faulting on.

To better assist you with your problem, what exactly is AVG telling you when it "prevents you from launching character sets?" As in, please paste either the exact error or a pic of the window. More detail is better.

Also, are you running ISBoxer in administrator mode? What about InnerSpace?