I had a similar observation a while ago - no mod would install and just break after a it downloaded telling me it failed (folder was empty afterwards).
The reason was identified (thanks to @Vantha!) that I had remainders (= saved games) of an old installation (0.25) on my harddisk and this conflicted with the mods somehow. Removing them solved the issue.
@nababuSuggest to have a look as well, maybe it helps!