Pete,

Probably a corrupt object code field. When you remove the code and then put it in again VFP has to recompile it for the Objectcode field in teh scx.

Make a copy of the scx/sct. Then

USE The.scx excl
REPLACE ALL ObjCode WITH ""
PACK
USE
COMPILE FORM The.scx

and see if that fixes things.

JimB