Hello Timothy.

I've seen similar behavior in combo boxes (mine not yours). My solution was a bit clugy (sp?), I forced a space after whatever the user typed then trimmed the result. That seemed to work.

Anybody have any better idea or explanation?

Well, this code, in my quickfill combo class works fine for me <s>.

This code in InteractiveChange:

*** handle the key...IOW, find the closest match in the list
IF This.SelStart > 0
	IF ( LASTKEY() > 31 AND LASTKEY() < 128 ) OR ( LASTKEY() = 7 )
	   This.HandleKey()
	ENDIF   
ENDIF

HandleKey method:

LOCAL lcSofar, lnSelStart, lnSelLength, lnRow

WITH This
  *** Handle backspace key
  IF LASTKEY() = 127
    .SelStart = .SelStart - 1
  ENDIF	
  *** Get the value typed in so far
  lnSelStart = .SelStart
  lcSofar =  LEFT( .DisplayValue, lnSelStart ) 
  *** Find a match in column #1 of the combo's internal list
  FOR lnRow = 1 TO .ListCount
    IF UPPER( .List[ lnRow, 1 ] ) = UPPER( lcSoFar )
      .ListIndex = lnRow
      EXIT
    ENDIF
  ENDFOR		
  *** Highlight the portion of the value after the insertion point
  .SelStart = lnSelStart
  lnSelLength = LEN( ALLTRIM( .DisplayValue ) ) - lnSelStart 
  IF lnSelLength > 0
    .SelLength =  lnSelLength	
  ENDIF	
ENDWITH


Keep in mind that his is a combo class with style=0-DropDown Combo. There is also code in the GotFocus() to ensure that the entire value is selected even when the user clicks in the combo.