I think you need to explain what you are doing a little better.
I just created a blank form based on a sample table with 4 fields. I added
a tab control to the form, and placed textboxes for two of the fields on tab
page #1 and two textboxes for the other two fields on tab page #2. I entered
data in the controls on tab 1, then clicked on tab page #2 and entered the
data for the other two controls. When I checked to see if I was still on a
NewRecord, I was; none of the data was written until I actually moved to a
new record.
Have you checked the forms "cycle" property (it is on the Other tab) to make
sure it says "Current Record"? If it says "All Records", and the tab order
of your controls is such that the control with the last tab index is on tab
page #1, then you may be leaving the record and going on to a new one.
Do you have any code behind your form, that might be firing and saving the
current record?
Do you have a subform control on the second tab page? If you have a subform
on the tab, when it gets the focus, you main form will also write the record.
To prevent this, you could hide the subform (or the tab page it is on) until
such time as your main forms data is written.
HTH
Dale