Just recently I was hunting a "null, null" error in a large ColdFusion application. It started occurring all of a sudden under decent load and it was unfortunately rather hard to reproduce.
Some basics: If you're getting a "null, null" error in ColdFusion (and yes, this still does occur in ColdFusion 8 and 9 occasionally, even though there was a certain known issue in CFMX 6/6.1 that was fixed…