Hello magi6162,
as the SelectionChanged event is not always called twice, even a separate counter wouldn't solve this problem. So I think the only way is to fix the bug in the dll...
@Filippo again: Please read this thread carefully and post a small answer if you can/can't/will/won't fix this bug in your dll. As an alternative you can post your actual source code (which includes your last additions) so someone else could be so cute to fix the bug. Thanks!
specci48