This shows the problem (at least in VFP6). I think the problem still exists. This thread is getting big enough that I don't know if you saw this downstream or not. :)

CREATE CURSOR PirillinoDelPicchio (a c(10))
APPEND BLANK
INSERT INTO PirillinoDelPicchio values("1")
INSERT INTO PirillinoDelPicchio values("2")
GO TOP

SELECT a,ISBLANK(PirillinoDelPicchio.a) FROM PirillinoDelPicchio

goto 2 in PirillinoDelPicchio
SELECT a,ISBLANK(PirillinoDelPicchio.a) FROM PirillinoDelPicchio