Try using another keyboard or USB socket. My wireless USB KB is fine and has been since day 1 on the XBox. Nothing has changed. Some people seem to have had issues with wired keyboards on different USB ports. My keyboard and mouse are both wireless connected through one wireless dongle plugged into the front of the XBox. Other than the losing mouse control bug(separate issue reported here) everything has worked fine. You may also want to try using without USB adaptors/hubs too.