Oh you mean cut the file back when it fails once rather than on any resume, much cleverer (cleverer a word?) idea. The 1 mb was just a pulled from the air figure.
I personally have never flound a problem with files that are large i have downloaded and resumed, I have a $CRC list of them and have downloaded some large ones and they match by $crc(filename) exactly when i recieve them from the orginals and even when i copy one to a cdr i have compared them later and they match (you would hope they do be detrected as faulty being zips), admittedly these are all coming from the same source (a client i keep up with them incase i cant get on the ftp with em), so maybe its sender related, i dont have that fastsend on, i think my packets are at 4kb as well by the way, no idea why tho.