Were there any other symptoms Dan?
My Alternator has a small amount of grease on it, from where the inner CV joint boot became detached.
I'll explain what the problem was. Basically, in a car with a normal working alternator, the output of the alternator depends on the current drawn by the car's electrics. But when you load up the electrics, the alternaotr increases its output by putting an increased load on the engine.
In my Punto, if I let it idle, and quickly turn on all the lights and full beams, the revs drop due to the increased load put on the engine by the alternator. It is only maybe 50 revs or so, but you can see it on the rev counter and hear it also in the pitch of the noise from the engine. The revs rise back to normal probably less than a second after they have dropped, as the car's idle control valve does its thing and lets in more air/fuel.
Now, when I had the charging/alternator problem, the small wire going to the alternator had a dodgy connection, and sometimes because of this the alternator wouldn't be giving an output (at idle, voltage on the battery was approx 12.5v instead of the normal running of 14-14.5v). If I gave the wire a wiggle, the alternator would kick in, which put the load on the engine and brough the revs down again momentarily. But the running problems were being caused by the wire vibrating and constantly cutting the alternator in and out, so there was a constantly changing load on the engine which caused jerkiness especially in traffic, it felt like it was going to shake the engine out of the car sometimes, when in traffic in 2nd gear.
Anyway, I hope that mini essay is of use to one of you.