Avast and Bluetooth?

I’m trying to help a friend install Avast! on his Dell Desktop using Vista. He uses a Dell Bluetooth mouse, and as soon as he installs and reboots, the computer keeps asking him to connect his mouse, acting like it’s being constantly reconnected. The bluetooth icon shows the mouse and keyboard as being off, but they still work. Any ideas?

Strange… what would avast interfere with bluetooth? ???
Which was the antivirus before avast? Operational system? Other security applications (firewall)?