i got the same thing
This is why i stopped using Sedo. I got a similar email beginning of November. I had rougly 200 domains registered with them, and 4 were doing really really well.
Then, a week before they were supposed to deposit my earnings, I got an email from them. My first impression of the email was that it was VERY unprofessional and insulting. For two days I was in a pi$$y mood cuz i thought i put in all that effort for nothing. My traffic was 100% legit, and it took a lot of hard work to do. Lots of linking, lots of site submission. I emailed them back with proof of that my traffic was legit and they eventually deposited the money, and emailed me back with," our systems show that your traffic was legit."
First, they should have emailed me the second they thought there was a problem, not 5 days before a deposit was to be made....it was as if they were saying, "oh sh!t, you really did make money with us, and now we gotta pay you this month. prove to us that you domains are really getting traffic with us or we won't pay you." It's like they were looking for reasons not to payme.....
Number two, they should have stats available to them that shows that the traffic is legit. I was a real sedo fan untill that email thing happened. I'm really not into the guilty untill proven innocent thing. By comming out and accusing me of cheating like that really turned me off.