The program

#include <iostream>
#include <locale>

int main() {
  std::cout.imbue(std::locale("fr_CA"));
  std::cout << 1;
}

crashes on a 32-bit laptop as well as on a 64-bit workstation,
for all compiler versions 3.4.3 - 4.0.2 (didn't check others)
with a segmentation fault.

And I believe it shouldn't crash (only perhaps throwing an
exception).