Ken -

 

That trigger fires on IE9 at all the different compatibility levels. 

 

After looking into things a little deeper, I tried adjusting the Browser and Document modes on IE9.  Our problem only occurs when we are in IE9 Document mode.  All other combinations of Browser mode and Document mode work fine.

 

The error message below is thrown when we are in IE9 Document mode

SCRIPT5022: DOM Exception: INVALID_CHARACTER_ERR (5)
Load.ashx?type=scripts&file=IE_Loader, line 3 character 19227