It's known issue/bug with Top, Left, Height and Width properties.

>Try this:
>
>

>SET STEP ON
>
>oForm = CREATEOBJECT("myForm")
>oForm.Show()
>
>DEFINE CLASS MyForm AS Form
>
>    PROCEDURE Show
>	
>        IF This.Height = 50
>        ENDIF
>	
>    ENDPROC
>
>    PROCEDURE Height_Assign
>        LPARAMETERS nHeight AS Integer
>        WAIT WINDOW "Height_Assign called" NOWAIT
>    ENDPROC
>
>ENDDEFINE
>

>
>When the IF This.Height = 50 line is fired, the _Assign code runs. nHeight in the _Assign
>is 250.
>
>What gives?