I use Logitech trackballs on all my desktop computers. On one of the computers, a few days ago I observed that the cursor kept drifting up on its own. Wherever I move the trackball cursor, it starts drifting up from there vertically until it hits the ceiling. 3 days ago, it drifted up rather fast - making it rather difficult for me to use that computer. Yesterday it still drifted up but more slowly. Today it doesn't drift no more. Very strange. I did absolutely nothing on my system. Did some googling. Not quite find anything useful. There were posts that said remove/delete the trackball device from Device Manager and re-install the driver. I was planning to do so in the weekend... but it doesn't explain why it doesn't drift no more on its own now. I had tried swapping different trackballs which were known to be good. Doesn't affect the drifting. It is definitely a software issue, not a hardware one. Rebooted the computer several times, didn't change the problem. I am scratching my head on this one...
Sometimes, even though the ball appears to be clean, there is a coating of...well, scum, on the wheels that contact the ball that won't clean off easily. You have to gently scrape that stuff off. Sometimes a pencil eraser works pretty well for that. There is also a logitech utility that comes with the trackball used to calibrate it and also to program some macros for the buttons. I think you should be able to clean the sensor wheels and then recalibrate and be ok. Hope that helps.
seems like I've encountered this in the past, but can't recall specifically what the reason was. I would check all mouse software settings in control system as well, and look for any non factory adjustments. I did notice something just yesterday, not exact, but similar. I have a pen tablet that is connected in an auxiliary manner, and sometimes I just leave it be while working on the laptop mouse. Well, if the pen is left resting on the tablet (inadvertently) it will override the laptop or any other mouse, causing weird issues like you describe. That's pretty easy to determine though. edit: cleaning the ball as above, yes. But the fact you tried several with the same problem, suggests software or wireless conflicts.
Thanks everybody for the suggestions. Sorry I had forgotten to post an acknowledgement. And update: I have no idea what's going on. The trackball cursor drifting problem still persists. Sometimes it drifts up slowly. Sometimes it drifts up very fast. Sometimes it drifts DOWN! And sometimes it doesn't drift. I have absolute touched nothing. I haven't even rebooted the computer between these drifts/no-drifts. The cursor has a mind of its own. Very inconsistent. And incomprehensible.
Just in case anybody is curious on this problem... The cursor drifting problem still went on many months without any resolution. Sometimes the cursor drifted left, sometimes drifted right, sometimes drifted up. Drove me nuts. But... last week, because of a different issue, I happened to have re-installed Windows 7 on this box. Afterwards, no more cursor drifting. Problem gone. So the conclusion is the cursor drifting issue was in the Windows operating system (or software nontheless). I absolutely have changed nothing on the hardware. Same trackball. Same cable. Same connection. (I had tried unplugging the trackball and replugging in many times, and tried different USB ports... nothing resolved the drifting cursor problem. So it wasn't a bad eletrical contact.) Wow... never would have thought it was a software thing.