Actually, the blue toolbar on the bottom of your screen, is not from Messenger Plus!
There has been much discussion about the blue toolbar.
Just search the forums and you'll find alot of threads.
Heres one for example:
blue searchbar... ;(
Anyway, did you uninstall with these instructions:
How to uninstall ad-ware/sponsor
Also did you use any antispyware program like "Adaware" or "Spybot Search & Destroy" ?