I noticed a bug where the messenger won't start after putting the computer to sleep (stand-by). At the moment i've managed to reproduce this bug all of the times i've tried it, so i guess something must be wrong in the Messenger Plus!'s coding. My computer and software specs are as follows:
Messenger:
Windows Live Messenger 2011 build 15.4.3508.1109
Messenger Plus! build 5.00.0.702
Computer:
Windows 7 Ultimate x64 build 6.1.7600
8GB of DDR3 RAM
Intel Core i7-720QM @ 1.6GHz
I hope that with this information i can be of some help so the bug gets fixed in future releases of this wonderful add-on. Thanks once again Patchou.