I am trying not to panic...but
My trackball stopped moving upwards...as usual I came here did my search and found this excellent tutorial. Maybe I should've wait since I was very tired and it was 1 AM but, how can I sleep when my curve is not in perfect shape! So I followed the tutorial with the fantastic gigantic pics and found so much lint it was embarrassing. I am surprised it did not stopped working earlier (yes, is always in my shirt pocket.)

Now is three AM and I have not been able to mount it back. It just wont reassemble (the white plastic piece over the little rolls with magnets.) I decided I just need to sleep and in the morning, I will see the "light" and get it done.