PS: This change was already implemented in previous releases. The first occurance was in Messenger Plus! Live 4.83.372 (17 Oct 2009)...
(EDIT: Like Chris4 already implied)
quote:
Changelog
Messenger tends to slow down when improper compatibility settings are set for msnmsgr.exe. The setup of Messenger Plus! now resets the compatibility settings set for Messenger in Windows Vista and above.