Rabbit,

when the belt was changed, the problem didn't came back for ~ 10 days. At this time, I did suspect some slippage from alternator or tensionner, but my mechanic said he checked these parts when he changed the belt and they were OK.

Now, with your hints of 1450 RPM at start is normal, I will try to investigate the feet/min from main pulley, belt and alternator to find out any slippage caused from bad tensionner, seised bearing, etc...

By the way, if I press gas pedal after start, everything works perfectly with charging system: 14.6 volts at battery and if I put a load (head lamps), the alternator drops only at 14.4 volts. So, I said to my wife to kick the pedal if she leaves the car running for a while after starting it (it was cold here few weeks ago...)

Thanks,
Normand