I'm getting straight forward with my game, and now it does not work anymore on IE. But it's still working on chrome and firefox... So i created a fiddle:
No errors at all. Essentially, it does nothing in $.playground().registerCallback
I've also tried to remove the code in $.playground().registerCallback, replacing it with just a simple alert. Then i placed an alert just before the $.playground().registerCallback to ensure previous lines were fine. I got this alert but not the alert in the $.playground().registerCallback.
Tested in IE9 and 8 and isn't working :( FF + Chrome is ok...