Default values change once I enter/change value in any field

[HackerMan]

I have set check/drop down box default values to blank or null, as in I don't want the default to be "No".

Whenever I enter a value into the primary key or change any field, all the defaults I have set change/revert to No.

how can I enter information/change fields in a form while keeping all other field defaults as null? and why does this happen?

[Beetle]

Are we talking strictly about boolean (yes/no) fields here?

Where have you set the Default values? At the table or form level?

If they are all check boxes, have you set the Triple State property?

[HackerMan]

Are we talking strictly about boolean (yes/no) fields here?

Where have you set the Default values? At the table or form level?

If they are all check boxes, have you set the Triple State property?

Yes, these were just the Yes/No type of field.
I set the defaults at the table level, not at the form level.

I did not change any triple state property - I'm not familiar with that, sorry I'm very novice with Access.

[Beetle]

By default, boolean fields are dual state, meaning they are only True or False (yes or no), with Null not being an option. In your form, open the property sheet for your check box, go to the Data tab and set the Triple State property to Yes. See if this solves your problem.

[Micron]

The only affect this property has is how the control looks when the field value doesn't contain a value. Yes/No fields cannot contain Null values according to AB
http://allenbrowne.com/NoYesNo.html,
so there is no "option" for null, thus there has to be another reason for the problem. You need to explain more about the form and any code that might be behind it. For example, one thing that can cause this is if you try to put unbound combo or checkboxes on a continuous form. What you do to one will propagate through all.