The bug is in vfp 5, which introduced ItemTips. From the help on ItemTips:

Remarks

An item tip is a small window that displays an entire combo box or list box item when the mouse pointer is positioned over the item. Set this property to true (.T.) whenever items in a ComboBox or ListBox control are longer than the width of the control.

Which would be really great, except with SQLSelect rowsource lists, you get the error you found. :-(

>The ItemTips bug? The row source is a SQL select statement. What is the ItemTips bug anyway? Thanks for the suggestion. I'll give it a try.