Please make sure you downloaded the correct version for Live Messenger 2009 first. Because conversation windows not flashing is a known problem if you use tabbed chats on Live Messenger 2009 and don't have the latest version.
The big blue download now button on the
download page will give you version 4.70.334, which is the last non-beta version, but
this version is not compatible with Live Messenger 2009.
A little
below the big blue download button you'll see the text
"Users of Windows Live Messenger 2009: download the latest compatible version of Messenger Plus! Live here (in beta)". That link will give you
version 4.79.0.353 which is compatible with Live Messenger 2009, but still in beta.
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