Did you empty your cache already?
Yes I did empty cache
Did you make sure that all files were uploaded via FTP?
Yep, binary upload through WinSCP and also tried to upload the zip and unzip in place, same result.
Did you check the folder / file rights?
Yes I did, I even did a test where aal folders were writable.
Currently running version 2.05+ Build 150520 which doesn't have the css problem.