Hi Wayne,
Such limits in vfp8 should be a bug ,i think. The best bet is to use VFP9 instead.Even if with vfp9,you also have to explicitly convert a string which length might be greater than 255 into a memory type field with CAST()in a SQL statement,eg.

CREATE CURSOR tmp(f1 c(10))
APPEND BLANK
SELECT REPLICATE('x',400) as col1 FROM tmp && raise the same error message as you mentioned
SELECT CAST(REPLICATE('x',400) as m) as col1 FROM tmp