Datamapper ORM in-table foreign key not working

[eluser]DaMaul[/eluser]
Ok after a couple of hours of head scratching I think I've solved the problem. I'll post my findings here in case anyone else encounters the same.

It seems that the latest version of datamapper relies on the codeigniter's CI_DB_mysql_result::field_data() method, which seems to be totally broken in version 2.2.0 (the latest official release, but it's fixed in the newest dev version).

So as far as I can see, the latest version of datamapper doesn't work properly with the latest official release of codeigniter!