>On a CheckBox, if you put a RETURN .F. or 0 into the Valid
>you can to leave the checkbox.
>
>The possible workaround is to put a NODEFAULT into the LostFocus,
>but this cut the code when you leave the form
>form.LostFocus
>form.Deactive
>are not fired.

This is a known issue, and was documented in "Hacker's Guide for VFP 7". I'm not sure if MS considers it to be a bug in the controls or a bug in the help. I suggest you submit this as a bug report on http://support.microsoft.com/default.aspx?scid=/support/vfoxpro/report/report.asp&sd=msdn