I've taken a look at the MSI.
1. The main issue seems to be that you don't have VSL as "Key file" for your component.
Just put it as first file in your file list (so that it is "Key file" to the component), and everything should work.
See the screenshot in the attachment (screenshot from ORCA).
2. The Solution publishing tool seems to mess stuff a bit with your setup...
To allow ALL languages for Visio 2013 (and not only German 1031), you could try setting Language=1
That is, in the MSI in the Qualifer column you should get "1\xx\Rackdesign.vsl".
Note that this does not seem work for all versions (in particular, 2003); only 2007 and above.
3. Come on, move to WiX already

MAKEMSI sucks

Please also mind the PM.