Hi,

i have found time for report this old bug.

Code for repro bug:

PUBLIC oform1

oform1=NEWOBJECT("form1")
oform1.Show
RETURN

DEFINE CLASS form1 AS form


	Top = 0
	Left = 0
	Height = 534
	Width = 688
	DoCreate = .T.
	Caption = "Form1"
	Name = "Form1"

	ADD OBJECT lb1 AS label WITH AutoSize=.t.,top=200,left=100,Caption='Change size and click on form; then move'
	
	ADD OBJECT check1 AS checkbox WITH ;
		Top = 32, ;
		Left = 37, ;
		Height = 17, ;
		Width = 60, ;
		Caption = "Move", ;
		Value = .F., ;
		Name = "Check1"


	ADD OBJECT spinner1 AS spinner WITH ;
		Height = 24, ;
		KeyboardHighValue = 72, ;
		KeyboardLowValue = 4, ;
		Left = 108, ;
		SpinnerHighValue =  72.00, ;
		SpinnerLowValue =   4.00, ;
		Top = 29, ;
		Width = 121, ;
		ControlSource = "THISFORM.FONTSIZE", ;
		Name = "Spinner1"


	PROCEDURE MouseMove
		LPARAMETERS nButton, nShift, nXCoord, nYCoord
		STORE MCOL() TO nXCoord
		STORE MROW() TO nYCoord
		IF ThisForm.Check1.Value AND POPUP('pp_test')
			MOVE POPUP pp_test TO m.nYCoord,m.nXCoord
		ELSE
			DEACTIVATE POPUP pp_test 
			DEFINE POPUP pp_test FROM m.nYCoord,m.nXCoord
			DEFINE BAR 1 OF pp_test PROMPT 'BUG BUG BUG'
			ACTIVATE POPUP pp_test NOWAIT
		ENDIF
		THISFORM.DRAW()
	ENDPROC


	PROCEDURE Destroy
		RELEASE POPUPS pp_test
	ENDPROC


ENDDEFINE

Run code.
Move mouse,
FROM clause on DEFINE POPUP is good,
if you change form fontSize, it remain good.

Check on CheckBox, this start MOVE POPUP use for popup position.
Move the mouse.
You can see a bug on linear trasformation from COL,ROW and x,y pixel
position of popup.
Because the coefficien for this trasformation are correlate with
form font metrics, i suspect this:
change form font properties, then bug coefficient change.

Yes it is true.

Change FontSize with spinner, click on form for read changes on
MOVE POPUP ( another bug ? ) and, moving mouse, you can see that the linear transformation is changed.

Then, workaround this bug is not simplex, but need to read form font properties for compute compensation coefficient.

This bug is present from version VFP3.

Exist a simple workaround?

Fabio