Speedo and tack dance

[SprintST]

Here's a new one on me. On the way home from Colorado my tack and speedo started to twitch. Sometimes together, but usually the tack did it more. It came and went, not dependant on mph or RPM, did t from anywhere between 4k-6k rpm, and over 60mph. I was on the interstate. It would run fine, restart after gassing up fine, just doing this wierd dance. Then, after it got dark the lights, including the dash ilumination, started to flicker. The good news is, 1) they didn't go all the way out, and 2) the tack and speedo stopped dancing. When at a stand still, I can rev the motor and the lights brighten.

I stopped in KC and poked around trying to find a loose wire, specificly ground. The battery checked out good, and the charging system seemed not to be fluctuating. I finished the ride back to St Louis, and rode it to work one day with no issues. But last night I went for a short ride. The needles dance even more now, and I thought I felt it cut out once or twice. The most obvious light flicker now is the 'driving light', it flickers even at idle. So now I'm stripping the body and tank off, again, to see if I can find anything else. Going to do a static test on the stator to see if it might be giving up.

Some background: after 1.5 years of use a stator went bad in my bike and was replaced under warrenty. I'm beginning to wonder if the rec/regulator is now giving up on me. That would seem to jive with the light levels dependant on rpm, but I'm not sure if it explains the needle dance. That would seem more like an intermittent ground issue.

Anybody got any ideas? Previous experiences? I don't relish the thought of leaving my bike at the dealer for the month plus it'll take for them to get to it. They're just that busy, not incompetant.