ComboBox en TSBrowse

[Armando]

Amigos del foro:

Buen inicio de semana, estoy usando la clase TSbrowse 7.01 de Manual Mercado y modificada por José Murugosa.

Cuando en una columna uso un ComboBox me tira un error al salir de dicha celda.

Path and name: C:\Metalona\SiaWin.Exe (32 bits)
Size: 747,520 bytes
Time from start: 0 hours 0 mins 18 secs
Error occurred at: 10/12/2006, 22:00:05
Error description: Error BASE/1111 Argument error: LEN
Args:
[ 1] = U

Stack Calls
===========
Called from: => LEN(0)
Called from: TSBROWSE.PRG => TSBROWSE:EDITEXIT(2962)
Called from: TSBROWSE.PRG => (b)TSBROWSE:LEDITCOL(4955)
Called from: TSCOMBO.PRG => TSCOMBO:KEYDOWN(68)
Called from: WINDOW.PRG => TWINDOW:HANDLEEVENT(0)
Called from: CONTROL.PRG => TCONTROL:HANDLEEVENT(0)
Called from: COMBOBOX.PRG => TCOMBOBOX:HANDLEEVENT(0)
Called from: TSCOMBO.PRG => TSCOMBO:HANDLEEVENT(56)
Called from: WINDOW.PRG => _FWH(0)
Called from: => WINRUN(0)
Called from: WINDOW.PRG => TMDIFRAME:ACTIVATE(0)
Called from: siawin.prg => MAIN(176)

System
======
CPU type: Intel(R) Pentium(R) 4 CPU 3.00GHz 3000 Mhz
Hardware memory: 503 megs

Free System resources: 90 %
GDI resources: 90 %
User resources: 90 %

Compiler version: xHarbour build 0.99.61 Intl. (SimpLex)
Windows version: 5.1, Build 2600 Service Pack 2


La misma aplicación en 16 bits funciona muy bien. Algo estoy haciendo mal ?

Saludos, Armando