Perhaps a novice question, but in the past couple of weeks my Apollos haven't been producing the same 24 hours rewards at litecoinpool - it's dropped. Please tell me it's not because of anything with the Apollos. The only change I've noticed is the difficulty has gone up from 8,917,884 to 10,360,375. Am I right to conclude "difficulty" = more work required of the Apollos and therefore less payout in a given 24 hour period?

Hey - like I said, I'm a novice but confirmation would be nice.