[fw-db] Specifying columns with Zend_Db_Table_Row::findManyToManyRowset

Hello,

How can I specify which columns to fetch when using Zend_Db_Table_Row::findManyToManyRowset?

I've tried passing in a modified Zend_Db_Table_Select object as the 5th parameter, but it seems I can only do things with like modify the where clause and order. Calling from() on the select object produces unexpected results because it implies another join. If I call from() and use the "m" correlation name, Zend_Db_Select throws an exception "You cannot define a correlation name 'm' more than once".

Any suggestions?

-Hector