Even when I used a different port, the problem persists. As for mouse change, I used another Microsoft Intellimouse I have, and the problem still continues.
On a side note, I tried both mice on my old computer and the problem is not occurring.
Could this be a driver conflict? :s I have tried uninstalling my mouse's drivers and it did not fix anything. The more I think about it, the less hopeful I am of regaining control of this computer.