Odd behaviour in CErrorHandler

Guys, this one is strange!! In trying to use the grid view I screwed up leading to an unhandled exception that is caught by CErrorHandler in CErrorHandler::handleException. In CErrorHandler::handle the app dies unexpectedly at the call to "instanceof" at line 107:

if($event instanceof CExceptionEvent)

  $this->handleException($event->exception);

else // CErrorEvent

  $this->handleError($event);

Been banging my head here!! Anyone have any idea why this would occur? Much thanks in advance!!

Bob

Is there a php error message? Any other information?