I have several of the TouchSLide units and have not had any problem with any of them. The only difficulty is on the Arduino that is controlling it. Most people do not use it in that fashion but write the code on the slide itself. To control it from the Duemilanove you have to use softserial which is not very reliable at high speeds
I am working on a library that will communicate via one of the megas extra serial ports and take graphic commands.
Mark