Xojo 2013r4.1 is working great!
Just a note for Web Custom Control users that Xojo 2013r4.1 includes the fix for Feedback item 29775. jQueryFileUpload works fine with 2013r4.1, as do the rest of the controls.
The Xojo team probably doesn’t hear this enough, so: thank you for your responsiveness and all your hard work on Xojo.