Barry, I was talking more about audio signals of low amplitude (like PC's or MP3 players output). We've had slight problems sometimes, when the rs-232 communication was really intensive. The problem was: no whielding in rs-232 comm, and (we found out later) low quality coaxial sudio cables, made in china, which instead of a shield had just a couple of shielding copper hairs runninr along the signal wire.

With LAN networks it can be tricky to notice if the signal has been altered, as TCP/IP has data integrity check/management integrated in the protocol.

But my practical experience has to mostly agree with you, it's just that sometimes you hit a brick wall, and you can't get around it for some time, until you discover that you had crosstalk/induction problems.But i agree CAT5 is excellent for running rs-232, for moderate distancies.