Hi,
ll
Microsoft AntiSpyware Program (originally owned by GIANT Company) is not that bad against Messenger Plus!
It's default action is 'Ignore', and in the warning message they recommend ignoring it.
Nothing really to worry about, however some users may delete Messenger Plus! under the influence that it may be bad spyware software...
Microsoft should detect whether or not the sponsor program has been installed, if not then it should not be detected as spyware.
Here is a screenshot of GIANT AntiSpyware concerning Messenger Plus!: