Sometimes there will be incorrect LF's when you initially change the seating configuration on a particular route.
For example, say you switch a flight from 162 passengers in a 737-400 to a 150 Y & 10 C config. The numbers in the statistics area reflect the 7 day average, so after the first day you might get something like 1 or 2 pax in C even though the particular flight was actually full of C pax. After a week has passed, the 7 day average should equalize and it should make sense again. I haven't experienced this recently, but its happened to me before.