autoexp.dat rule not running

I have a template defined thus...

Code:

---

namespace stdi3
{
    template <typename T, const size_t MAX_SIZE>
    class fixed_vector
    {
    private:

        size_t current_size;
        T buffer[MAX_SIZE];
    };
}

---

I have a rule in the autoexp.dat file at the start of the [Visualizer] section.

Code:

---

;------------------------------------------------------------------------------
;  stdi3::fixed_vector
;------------------------------------------------------------------------------
stdi3::fixed_vector<*,*>{
  preview(
    #(
      "current_size = ", $e.current_size
    )
  )
}

---

When I debug and watch a stdi3::fixed_vector object my visualizer rule seems to be ignored.
Any ideas where I may be going wrong?
I'm using VS2008.

I've also tried this, but no luck either.

Code:

---

;------------------------------------------------------------------------------
;  stdi3::fixed_vector
;------------------------------------------------------------------------------
stdi3::fixed_vector<*>{
  preview(
    #(
      "current_size = ", $e.current_size
    )
  )
}

---