Problem with Wacom Tablet mouse while using Lightroom 3.

[Huntertitus]

Hello. This is my first post. I have a problem which started today. I am using Lightroom 3 on a Mac (Osx 10.6.8). I use a Wacom Intuis 2 tablet with a pen and a mouse. These work fine on the computer with all other applications. However today, when I launched Lightroom the mouse wouldn't work at all although the pen still does work. I am not aware that I changed anything on Lightroom but I feel I must have accidentally. I have been using the tablet, pen and mouse for years with no problem like this before. Any idea how to get the mouse working with Lightroom again? When I attach an external Apple mouse it works fine with Lightroom, so I don't know what the problem is. Any answers to this trouble would be very welcome!