std.algorithm Map using a external variable

[Zardoz]

I'm trying to use Map with a code like this :

...
   immutable int m = 10;
   int[] caca = [1,2,3,4];

   auto caca2 = map!( (a) {return a * m;})(caca);

   writeln(caca2);
...

I get a Segmentation fault some times:
The most interesting point it's that depends of the code around 
of it ins the same  program. for example If a use getopt at the 
begin of my program, then seg fault, etc...
  Looks that there some weird error in gdc 4.6.3

PD: Later I will put the whole code so any can see if I doing 
some weird thing that make map crazy