Set the Forms cycle to Current Record. On each tab control, put a little unbound text box, colour it the same as your forms background (so it's not visible on enter) and on the OnEnter event of the text box do:
Me.(NextField).setfocus
Remember, if you are moving to a subform, you need to reference the subform and it will move to the first field of the subform, ie: Me.subformname.SetFocus. On the last tab control, have one which goes back to the first field on the first tab. You'll need to create another way for users to move through records, combo box to select info based on form.
The other thing to remember is, make sure that each unbound text field is last in the tab order for each tab control.
HTH
DBL