The extension shouldn't cause a problem. What exactly is the trouble that you're experiencing?
Concerning the rest of you question, queues or notifiers either one would work--and would be better than a global. Your selection between the two depends on the functionality that you want. A queue allows multiple locations to write to a common FIFO and the receiver will see all the messages in the order they were written. With a notifier, a value can be overwritten if the receiver doesn't read fast enough.
Mike...
