I have a Kensington Expert Mouse (USB trackball) and have the same issue. I also have Virtual Box installed and am a member of the vboxusers group. The issue does not exist in the guest session either.
I have a Kensington Expert Mouse (USB trackball) and have the same issue. I also have Virtual Box installed and am a member of the vboxusers group. The issue does not exist in the guest session either.