Ok, more info.

The EditBox class has the following code in KeyPress coming from MereMortals:

LPARAMETERS nKeyCode, nShiftAltCtrl

IF ISALPHA(CHR(nKeyCode)) 
   NODEFAULT
   nKeyCode=ASC(UPPER(CHR(nKeyCode)))
   DODEFAULT()
ENDIF

First of all, should it be DODEFAULT(nKeyCode, nShiftAltCtrl)?

Secondly, I put the following code in LostFocus of editbox just to test:

this.Value = this.value
=MESSAGEBOX(this.Value)
RETURN DODEFAULT()

The first time I tab out of the editbox, it shows empty messagebox. If I position the cursor in the Editbox and tab out again, it shows the value.