I don't know the function READ() (not in VFP7) so can't comment on that.
Can't see anything untoward with the majority of the code.

>...

IF READ()<>4

 SKIP
 IF EOF() OR bookinno<>BOOKINSTORESHEAD.bookinno
  GO mrecno
  this.Parent.Parent.Parent.cmdinsert.Click()
 ELSE
  GO mrecno
  skip

  thisform.pageFRAME1.page1.grdBody.Refresh()

*************** WHAT HAPPENS IF HERE PUT IN thisform.pageFRAME1.page1.grdBody.SetFocus() ?
*************** That should be enough to get you to the next row.

  *KEYBOARD "{DNARROW}" PLAIN
**************  Was this meant to select next line of grid or activate the drop-down list?
**************  If the latter then put "KEYBOARD '{F4}' PLAIN" in the GotFocus() of the combo
 ENDIF
ENDIF
>
>

HTH

Terry