EDIT: As of Revit 2010 SP3 (could have been earlier), the following is no longer a problem. Thanks for listening!
No, this post won’t discuss such political issues. We’ll leave that to Lou Dobbs on CNN.
A lot of users enter symbols in Revit or any other application, by typing Alt + a series of digits. For example Alt+0178 results in ². In Revit 2010, this will work for the first character you type after using this technique for the first time since installing the application. After that, your screen will be taken over by foreign characters with each subsequent try.
It seems to keep changing with each try, even though you use the same digit combinations. I hope this gets fixed soon! In the meantime the workaround is to go to the Character map and copy & paste the symbol from there.