[tacosoldier]

1999 Oldsmobile Intrigue
Estimated 136,000 miles

This doesn't happen very often, but at random times my Olds won't start. When it happens, I return to my car, turn the key to crank the engine, nothing cranks, the performance cluster lights come on, nothing seems faint, radio comes on and ac.
Early this year, I had Sears put in a new battery, then the problem seemed to disappear. Then after some time later, the symptom returns. After several tries, the car would start.
I took my car to Sears to check the battery, the battery was fine. I did request that they replace the cable bolts. Then later, I took off my altenator, and had a parts store check it. The altenator failed, bought a new one and put it on. No problems.
Now about a month later, the symptom has reared it's ugly head again. It same, go to start car, nothing happens, no cranking, not even the slightest, the dash lights come on like normal. After a few tries, the car will eventually start up. I do have a battery monitor, when this happens, I turn the key to the off position, plug in my battery monitor. The monitor shows a full charged battery, 12.7 - 12.6, then when I turn the key to start, the monitor shows that the battery voltage drops to 12.3. Luckily I was parked near a repair shop and asked one of the guys to jump my battery, he said that the battery is holding enough juice.
So now I wonder, could the recently replaced altenator be the culprit again? I think it's possible that my starter could be malfuntioning. However, my service manual said that this rarely go out. The other culprits, which I hate would be the ignition switch. Could my key be a factor?

I'm at a loss and frustrated, I've been late to work because of this. Is there anyone that has experienced this before?