Hello, is here no one running same version MWG 6.8.7 / 8378 and can just try the posted donwload link with IE7 / IE8 and post the result?
We found the solution in our own environment.
We are using Sophos antivirus. Sophos installed the IE Add-On ""Sophos Web Content Scanner".
When deactivating this Add-On the "Save as..." dialog appears immediately.