I had the problem only once - the first two times i installed it were fine. Guess its one of those things, eh guys!
See yas online - also aka Cheese_Hunter or Mulla_Kintrye
Found a fix!
Sorted, dont panic- there is a tiny download registry fix (self installs) do a google search for <MOHAA spearhead registry fix> or similar :) that did it for me.
I can email it you if you have no luck finding it.
hope this helps :)