I have a logitech laser mouse - no model number, but came with Logitech comfort keyboard/mouse combo. The problem is the mouse is losing focus. Examples - 1) when I highlight a paragraph, it loses part of the highlight before I've completed. 2) When highlighting an area in photoshop, it makes the selection before I've finished defining it. 3) When dragging messages in Thunderbird, it 'lets go' as I'm dragging and drops the message in the wrong place.

It doesn't appear to be software as I've deleted the drivers and downloaded new ones, and the fact that a different mouse doesn't do this makes me certain it's a hardware issue. However, before it goes in the bin, are there any known issues with Logitech mice doing this?