although as Sergey suggested, the code in the mouseup fixes the display afterwards (see text1 on the form compared to text2):

oform = NEWOBJECT('formtest')
oform.show()
READ EVENTS


**************************************************
*-- Class:        formtest 
*-- ParentClass:  form
*-- BaseClass:    form
*-- Time Stamp:   04/21/04 10:06:04 AM
*
DEFINE CLASS formtest AS form


	Top = -1
	Left = 0
	DoCreate = .T.
	ShowTips = .T.
	Caption = "Test Form"
	Name = "FrmTest"
	Width = 270
	Height = 250
	AutoCenter = .T.


	ADD OBJECT cmdclose AS commandbutton WITH ;
		Top = 192, ;
		Left = 85, ;
		Height = 27, ;
		Width = 84, ;
		Caption = "Close", ;
		Name = "cmdclose"


	ADD OBJECT text1 AS textbox WITH ;
		ControlSource = "m.fname", ;
		Format = "!", ;
		Height = 23, ;
		InputMask = "XXXXXXXXXXXXXXX", ;
		Left = 48, ;
		Top = 36, ;
		Width = 168, ;
		Name = "Text1"


	ADD OBJECT text2 AS textbox WITH ;
		ControlSource = "m.lname", ;
		Format = "!", ;
		Height = 23, ;
		Left = 48, ;
		MaxLength = 15, ;
		Top = 72, ;
		Width = 168, ;
		Name = "Text2"


	ADD OBJECT text3 AS textbox WITH ;
		FontName = "Courier New", ;
		ControlSource = "m.fname", ;
		Format = "!", ;
		Height = 23, ;
		InputMask = "XXXXXXXXXXXXXXX", ;
		Left = 48, ;
		Top = 108, ;
		Width = 168, ;
		Name = "Text3"


	ADD OBJECT text4 AS textbox WITH ;
		FontName = "Courier New", ;
		ControlSource = "m.lname", ;
		Format = "!", ;
		Height = 23, ;
		Left = 48, ;
		MaxLength = 15, ;
		Top = 144, ;
		Width = 168, ;
		Name = "Text4"


	PROCEDURE Init
		PUBLIC m.fname, m.lname
		m.fname='ABCDEFGHIJKLMNO'
		m.lname = 'ABCDEFGHIJKLMNO'
		DODEFAULT()
	ENDPROC
	
	PROCEDURE Destroy
		CLEAR EVENTS
		DODEFAULT()
	ENDPROC

	PROCEDURE cmdclose.Click
		thisform.release()
	ENDPROC

	PROCEDURE text1.MouseUp
		LPARAMETERS nButton, nShift, nXCoord, nYCoord
		This.SetFocus() 
	ENDPROC

ENDDEFINE
*
*-- EndDefine: formtest
**************************************************