if you change it to datetime and then change your insert to inlcude the nano seconds it will break.
that is why the convert was needed. When you instert 06/22/10 you are actually inserting 06/22/10 00:00:00.000 but in his data he actually had valid times stored with the date. this needed to be dropped to create non-unique values.
Dan
If only I could snap my figures and have all the correct indexes apear and the buffer clean and.... Start day dream here.