Serial comunication and reset

Hi all, In some tests I made Arduino seems to do a reset (invoking setup function) every time begin a serial connection. Is this the right behavior? It's the Adruino bluetooth working in the same mode?

My code it's really simple, in seup() there is Serial.begin(9600) and in loop it check with Serial.avaiable if there is something to read and put it in a buffer.

Thanks Fabrizio

That is standard behavior. Some of the *duinos have a jumper to stop that from happening but I don't think the Arduino does.

Many thanks. Meanwhile I've disovered that this behavior isn't present in Arduino BT that I'm using for the project. When I posted the question Arduino BT wasn't in my hands and I was developing software with an Arduino Diecimila.

Thanks again Fabriio