Oh btw, which version of Screenshot Sender is it? 3.0.555 ?
If it still doesnt work, let me know
It looks if i solved the problem...
It was not your plugin that was the problem, I was running MSN Messenger in "protected mode" with some sort of program/addon called 'SurfRight'. This SurfRight takes away some 'admin rights' so it is more safe to use MSN Messenger.
I think that was the problem... thanks for your time and help!