Thanks anyways, Gaz!

No. I neglected to mention I use this before the select:

DBCC TRACEON(8765)

However, I still get

Msg 8114, Level 16, State 8, Line 2

Error converting data type DBTYPE_DBTIMESTAMP to datetime.

when I...

Those are the values for A_D.guardian1_attended_date (from the query above). Yes, there are only 2 rows that are joined.

Thanks, Gaz, but that's not it.

The MySQL values are:

2013-02-03 00:00:00.000

2013-02-11 00:00:00.000