Exceptions not caught

I'm experiencing a very strange issue one of my servers, and I can't seem to track it down - basic exception handling doesn't work.

The following script:

echo "Exception Test<br>";
try {
  throw new Exception ("myException");
} catch (Exception $e) {
  echo "Caught!";
}

Produces: Fatal error: Uncaught exception 'Exception' with message 'myException'...

Any ideas? Is there some setting that might be screwed up somewhere? I'm using XAMPP on Linux, PHP 5.2.3.

Thanks a bunch!!