Odd. We used the wait time iphone app obsessively in the parks last week and it was always spot-on for us, within reason (sometimes said 70 minutes when it was 80, or 20 minutes instead of 15, but usually updated to those following).
The wait time app was even what clued us in to Test Track being reopened a day early...we were across Epcot and saw a time pop up, which we chalked up to a mistake, but when we walked over, sure enough they were offering fastpasses and letting folks into standby!
Rides do occassionally shut down temporarily in the course of a day and we always assumed that was what was happening when a ride was listed as CL. We never saw one listed with CL for more than a very brief while unless it was, of course, legitimately down, like Splash Mountain.