Well, thanks all for your answers and sorry about my poor english...
This evening i'll try the solution you say, turning off the mute signal on emplode. I'm sure the cable is not in contact with any other, and it has no volts when Rio is unplugged. Maybe this cable is affected by the current flowing through other cables too close... Of course i have an alternator noise problem too, probably due to the installation that i'll fix when i have some time.
So when i put the Rio in the car the icon appears, but at home i cannot reproduce it. I'll try to reroute the installation too.
But I have a dude... The icon appears but volume is not changed... Is it the normal operation?
About the remote:
Probably the battery on the remote is dead. But it has a rare dead, couse it went from live to dead in 5 minutes, just the time to charge the new (July) Hijack. I have the newest now, so tomorrow i'll tell you if it was the problem...

So taking the opportunity of having your attention, a question:
Can I mix Rio remote signals with Pioneer ones? I have both and it would be nice to have both operating...
What must I do to tell Riocar I have a Pioneer remote?

Thanks very much for your time...
Cheers:

Miguel
Madrid (Spain)

10Gb blue Riocar on a Seat León FR 20vt