I'm having the same problems too! I uninstalled "Msg Plus!", reinstalled it with the sponsor and uninstalled it again. I don't have any adaware or hijack this programs, but it still keeps coming. I know it comes from messenger plus because there are many forums on the net that discuss how to remove the Msg Plus ads. Your earlier versions didn't have this problem, maybe you made a mistake.
Please remove search2web from your sponsors because it is ruining my system. I'm not going to run msg plus until you release it again with a sponsor program that isn't totally bugged. Find a different sponsor that just displays pop-ups and that doesn't change your system, desktop, search bar, homepage and settings.