Right. Just been doing some diggining around. Found this:
http://www.wilderssecurity.com/showthread.php?t=30511 . People who know Patchou (Messenger Plus programmer) say there is a "sponsor program" you can opt to install, which installs adware from lop.com, but if you opt not to install it, you don't get adware.
However, some other people claim they installed Messenger Plus, and despite opting NOT to install the "sponsor program", there was spyware left on their system, and the msgplush DLL (installed as part of Messenger Plus) bound itself to every process that connected to the Internet, despite the fact it had no apparent purpose.
Assuming all that is true, it looks extremely suspicious.