AdSense incomes dropping?

[altyfc]

Are there many users of AdSense here?

I know we can't talk about the specifics of the stats but I'd like to see if any other users are noticing any similar trends to those that we have experienced. We have AdSense across a number of large and popular sites, including one site serving well in excess of 100,000 uniques per month. The program has served us well - and continues to do so; however, in the last week or two, I have noticed income drop significantly (yet our impressions/clicks stats remain the same). Is anyone else out there using AdSense seeing the same, or is it something that's particular to us?

Thanks

Aaron