Yeah, it should be the same on both, but there are a bunch of reasons why it could be different -- one bad cable of three (missing ground or something) on component but you used a different cable for composite, maybe the composite has a floating input amp vs. ground referenced for component...

I'm just guessing here, of course, but I have seen odd little differences like this confuse people for weeks

M60ti, VP180, QS8, M2ti, EP500, PC-Plus 20-39
M5HP, M40ti, Sierra-1
LFR1100 active, ADA1500-4 and -8