For info, the latest available update is now the build 281.2. It's (almost) the same as the build 281.1 + the installer has a fix for French users.
Click the for Update option in the Help menu to install this update if you have an older version. You can also manually download this patch and/or previous ones in the Fusion 2.5 Owner's Lounge private forum (register your serial in your settings to get access to this forum).
Note: Steam users automatically get the latest update if the update option is set to automatic in the Steam client.