Since upgrading from 2011.2.2125 to 2011.2.2159 we have been getting "out of stack space" errors when clicking on an item in a webdatamenu. We have even taken out all the code from the client side click event and it still occurs.

The error is in ScriptResource.axd, in the call to _validateParams.

Type.prototype.inheritsFrom = function Type$inheritsFrom(parentType) {
    /// <summary locid="M:J#Type.inheritsFrom" />
    /// <param name="parentType" type="Type"></param>
    /// <returns type="Boolean"></returns>
    var e = Function._validateParams(arguments, [
        {name: "parentType", type: Type}
    ]);
    if (e) throw e;
    this.resolveInheritance();
    var baseType = this.__baseType;
    while (baseType) {
        if (baseType === parentType) {
            return true;
        }
        baseType = baseType.__baseType;
    }
    return false;
}

The call Stack keeps repeating as follows:

  Type$inheritsFrom JScript
  Sys$_isInstanceOfType JScript
  Function$_validateParameterType JScript
  Function$_validateParameter JScript
  Function$_validateParams JScript
  Type$inheritsFrom JScript
  Sys$_isInstanceOfType JScript
  Function$_validateParameterType JScript
  Function$_validateParameter JScript
  Function$_validateParams JScript
  Type$inheritsFrom JScript
  Sys$_isInstanceOfType JScript
  Function$_validateParameterType JScript
  Function$_validateParameter JScript
  Function$_validateParams JScript
  Type$inheritsFrom JScript
  Sys$_isInstanceOfType JScript
  Function$_validateParameterType JScript
  Function$_validateParameter JScript
  Function$_validateParams JScript

Any ideas?

Confirmed in Ie8 and ie9 with subtle differences.