I'm facing a problem after upgrading to sencha 2.1. I downloaded the latest fix for 2.1 from your code.
The problem I'm facing is that if I have your slider on the same page as other sliders on my page, then the other slider don't take their initial assigned values. Let's say they are from -10 to 10. And I give it a value of 0. So it will be initialized with the slider all the way to the left. But as soon as I comment out the code from your slider at the bottom, they come in the center.