Alternator, Maybe???

I've got a 96 grand prix with the 3.1. Here's a quick low down. May of

2002 I had a new alternator (lifetime warranty from NAPA), June 2002 new battery. Everything was good until September 2003. Alternator went out. I replaced that and not too long after that I was getting an dimming or pulsating of the lights. Not all the time but quite often. I let it go and just recently it was doing it all the time. Some of the dash lights have been coming on too (airbag, ABS, check engine). So tonight I notice that the lights are pulsating anymore and then everything starts to get a little bit dimmer and dimmer and then boom there's my battery light. So I'm assuming I've got another alternator shot. Now is it possible that the voltage regulator was no good on the last one causing the dimming and pulsating? And is it possible that I've just had bad luck with the alternators lately. This will be number 3 in less than 2 years. You guys seem to diagnose this stuff pretty well so I'd figured I try my luck here. Thanks in advance