I have had a similar issue when linking multiple sub forms to one master one trick that I find quite useful sometimes is instead of linking the sub form using the forms field control, I do the following. 1. Remove all links between the sub form and the master form 2. Open the sub form in another windows and in te data tab select the table that it is linked to and instead of the table click the small icon on the right to open in query window 3. In the query editor select all the rows from the table and the select the particular column that u wan to link with the master and in the criteria for that define the path to the linked field in the master form u can use the builder for that it wil be something like forms!frmMaster.controlname and save and close the query and form 4. On the before update event of the sub form you'll need to write a small procedure to auto update the linked field with the master form field as it won't do it automatically like it did when it was linked Something like Me.controlname.value = forms!frmMaster.controlname
This should solve ur problem