CCK Field Title Sorting

This has turned out to be pretty frustrating. When CCK fields are presented in the create node form, the fields are sorted in an unusual and unidentifyable manner. I have tried to use numeric prefixes on the field names and titles to force the sorting, but the more fields I add, the more the sorting changes up.

This is the order the fields are presented in the Manage Fields display:

1.0 Name                     field_1_0_entity_name 		 weight=10   Text	
1.1 Physical Address     field_1_1_entity_address_physic  weight=9     Address	
1.2 Mailing Address      field_1_2_entity_address_mailin  weight=9     Address	
1.3 Entity Type            field_1_3_entity_type                  weight=8    Text	
1.4 Subtype                 field_1_4_entity_subtype            weight=8    Text	
1.5 Phone                    field_1_5_entity_phone               weight=7    US & Canadian Phone Numbers	
1.6 Fax	                       field_1_6_entity_fax                    weight=7    US & Canadian Phone Numbers	
2.0 Known By              field_2_0_known_by                    weight=6    Node Reference	
2.1 Assigned to Research   field_2_1_assigned_research 	weight=6    Node Reference	

This is the order they come out on the create node form:

1.0 Name: *
1.2 Mailing Address
1.1 Physical Address
1.4 Subtype:
1.3 Entity Type: *
1.5 Phone: *
1.6 Fax:
2.0 Known By:
2.1 Assigned to Research:

Can somebody tell me what is driving the sort or help me figure out how to control the sorting of field names on the create node form? BTW - I cannot completely depend on weights, because I will have too many fields on the form and will run out of available weights. The above example is just a subset.

Thanks for your help.