Max IDE Cable Length?

[Fritz]

I purchased some of those new-fangled "round" IDE
cables the other day.  They're much easier to work with
and they probably do allow better air flow in the cabinet.

These cables are 24" long.  I was under the impression
that the IDE Spec limited cables to 18".  The salesman
said "I'm sure that they're OK, otherwise no one would
be making them and we wouldn't be selling them".
Well, with logic like that I promptly opened my wallet
and ....

Has it got anything to do with the old ATA/33/66 vs. the
new ATA/100/133?  Or the old 40 conductor vs. the new
80 conductor?  Anyone have any clues about this?

The system *seems* to work fine.  Perhaps, my data is
quietly being corrupted, bit by bit ............ :-(

Fritz Kolberg