Sandy,

since SP2 has the nasty habit not to show tooltips in gridheader anymore, and VFP10 is not due to come I believe your best option, and not only for that reason, is to make use of the class made by Carlos : Ballontips in VFP please go to http://www.ctl32.com.ar/ctl32_balloontip.asp.
Regards,

Koen