Stringy Weirdness

[1100110]

I haven't been quite able to figure this one out.

string[string][]       Dict;    //sure ok.
alias string[string][] dict;    //Error

void main()
{
     Dict                   = [["Cow":"moo" 
],["Duck":"quack"]];//cool
     Dict                  ~=  ["Dog":"woof"]                   
//No prob.
assert(Dict==[["Cow":"moo"],["Duck":"quack"],["Dog":"woof"]]);//looks 
legit
     dict temp              = [["Cow":"moo" 
],["Duck":"quack"]];//Error
     string[string][] temp2 = [["Cow":"moo" 
],["Duck":"quack"]];//Error


     //And My favorite one of all:
     auto temp2 = [["Cow":"moo"],["Duck":"quack"]];  //Error
}

I've hit stuff like this before, and I've always assumed it was 
just karma for screwing with it.  I can't figure out why it does 
this.