What you can do is edit the database design. It sounds like you entered layout mode and created multiple copies of the same container (picture) field. Since these are copies of the same field, you get the results you've reported.
Do this instead:
From the layout where you want to add more picture fields, select File | Manage | Database and click the fields tab if it is not already selected. Enter a new field names in the text box at the bottom such as Picture2. Select "Container" from the field type men and click "Create" to create your new field. Repeat this for each new picture field you need. Click OK to dismiss Manage | Database to return to your original layout.
Enter layout mode and drag the field tool down to where you want to add a picture field, Select "Picture2" (or whatever name you gave your new field) as the field you want and click OK. You'll now see a new field on your layout with small black boxes at each corner. You can change the size of your field by dragging these "handles". Return to Browse mode while saving your changes and you've added a new container field to your layout.