This new build of MSN Messenger has been removed because of a new 80048883 error that started showing up and prevented the use of build 7.5.322. The Previous version (7.5.311) has been re-added as the download on http://messenger.msn.com. We are investigating what we can do to fix the 80048883 error found in build 7.5.322.
A new version of MSN Messenger was released on http://messenger.msn.com yesterday that is an update to MSN Messenger 7.5. This new version (7.5.322) should help resolve many of the 80048820 errors that were occurring when signing into MSN Messenger 7.5.