That's weird.
Can't test right now, but I'm sure this should work:
Code:
#include <string>
#include <vector>
#include <algorithm>
using std::string;
using std::vector;
using std::sort;

typedef vector<string> strvec;

int main()
{
  strvec strs;
  strs.push_back("kjla");
  strs.push_back("afa w");
  strs.push_back("sgcsf");
  strs.push_back("s3ss");
  strs.push_back("3ggxt");
  sort(strs.begin(), strs.end());
}