If you live in a non english speaking country you may encounter problems when using Wizards of the Coasts’s online Dungeon & Dragons Character Builder on a Macintosh. You probably won’t get any further in the login process than this:
This is apparently due to a bug in WoTC:s implementation of the Silverlight-application, but don’t worry – there is a simple solution!
Whenever you want to run the CB you need to change the region settings in OSX. Go to System Preferences -> Language & text -> Formats, and change ”Region” to English-USA.
Ta-da! Now it should work. Just remember to change the settings back again when your are done.
Happy gaming!
Piruett 
THANK YOU!
I’m using Lion on an iMac 2011 and I could not figure out why this wouldn’t work. Did as you suggested and now works fine!
Poor implementation but now that it works I’m happy.
THANK YOU!
GillaGilla