Relationships, Referential Integrity And Subforms

If someone can help solve this for me, I would be forever grateful. I have attached the database to which I am referring for clarity.

I am creating a database designed to input data for morbidity and mortality at my hospital. I have set up four main tables: tbldemographics (basic patient information), tbladmissions (information about each different admission a patient may have), tblmorbidity (information about each untoward event suffered by a patient, which I would like to have linked to the specific admission, not just the specific patient), and tblmortality (information about a patient's death, which I would also like to have linked to the specific entry in the admissions table rather than linked to the more general information in the demographics table).

I have created relationships which I thought would work--but with referentail integrity invoked (which it seems like it should be), the very first key stroke on the form that I created to input the data (frmmain) results in an error message that the record can not be added or chaged because related record is required in tbldemographics--and yet this is the table to which I am inputting the data! Turning off referential integrity stops the error, but I don't want to just blindly do that--seems risky.

Problem number two: when I disable referential integrity and enter data into the demographics section of the form, any entry at all results in an automatic entry into the admissions table--even if I haven't entered that part of the subform yet. So if I then exit the form and return later, ANOTHER entry into the admissions table is made--again, even if I have not ventured into that subform yet. So that table winds up with bunches of entries with little to no data, which are NOT cleared up with a compact and compare maneuver.

I'm at a loss on both of these issues. I apologize for the long post, but appreciate any ideas you all might have.