It sounds like you have two different issues here. I will address them both separately.
Originally posted by gypsyrover
With 10.2.5 & 10.2.6 Finder aborts spontaneously and restarts.
This happened to me when I upgraded to 10.2.3; every time I tried to do something in the Finder, it quit and restarted to the point it was at before. If I opened a folder, it quit and reappeared with the folder closed. I had to downgrade back to 10.2.
The cursor tracks OK but after a rest it often jumps to near an edge WHEN I next use it. From there it tracks OK, again for some time.
This sounds more like a workspace issue than anything software. Are you using an optical mouse? If so, then make sure it is on a surface with an even (preferrably solid) color. I used to use a black mouse pad that said, in white letters, "01.01.00 The Mark of the Millenium", but I exchanged it with a solid green mouse pad because the cursor kept jumping across the screen when I moved over the letters. If you have a wildly contrasting mousepad/surface, put something down that has the same color over the whole thing.
If you don't have an optical mouse, a) why the hell not? and b) you might have a problem with the mechanism. Take the ball out and clean out the hole and the little rollers inside. Also do this if you have a trackball. If you're using a trackpad, you might want to invest in a mouse (they have very tiny mice that take up almost no space) or trackball (because you don't have to move them).
I hope this solves your problems... if not, then I'm not sure what you should do (or what the problem is).
