I'm experiencing the exact same problem as georgc wrt to the example. We're are also using 3.4 in an application and can't move the slider at all. I can click to move it to a value, but I can't drag it to another value. This is Windows 8 and IE10. I've looked at the fixes for IE10 and think I inserted them as required. But, this slider problem still exists in IE10.
Okay, just to ask when that might be expected? Also, just wanted to add that in the slider example, if I click on the slider, the thumb will move to that point. It's just that dragging support for the thumb is lacking. If you have a suggestion for a work around, I'd appreciate it. Thanks!
added a reference to it in my web index.php file, and it worked. I can now drag the slider thumb in my web page app to change the value in IE10.
So, if folks are having similar problems, here's a possible fix. BTW, I did also go to ext-base-debug.js and ext-all-debug.js files and made some changes there to account for IE10, though it wasn't until I added this override code that the slider worked as expected.