DMZ 1.7.1 (DataMapper OverZealous Edition)

[eluser]dejavu[/eluser]
I've got a bit of oddness happening in DataMapper DMZ. I'm somehow triggering an error:

In line 603

Code:

// Get and store the table's field names and meta data
$fields = $this->db->field_data($this->table);

I get the error:

Fatal error: Call to a member function field_data() on a non-object in C:\Users....

But if I add a call to get_class_methods($this->db) just before this line, it works:

Code:

// Get and store the table's field names and meta data
echo "<pre>"; print_r(get_class_methods($this->db)); echo "</pre>";
$fields = $this->db->field_data($this->table);

Apparently the get_class_methods() call somehow triggers an autoload that wouldn't otherwise be called??? Any suggestions what I can look at to fix this without patching DataMapper?