slre_cap issue

In a small C program under Windows, I did this regexp:
...
  struct slre_cap caps[10];

  const char *reg="(([a-z]+)/([a-z]+)@)?([a-z]+)(:(\d+))?";
  const char *src = "server:4100";

  slre_match(reg, src, strlen(src), caps, 10, 0);
...

Seems to work, but the caps structures are filled with incoherent data !?
