By any chance are you seeing something like this:viewtopic.php?f=14&t=4434
(As an aside, we put out rules for this a few weeks ago)
I am having the exact opposite problem.
When I log in as admin I see 8GB of traffic. When I go to the domains list I see not more than 2.4 !
Some domains even have close to zero traffic when awstats shows clearly 3GB traffic.
And attacks on the server are very very low generally.
Also in the resseler which these domains belong traffic shows up normally like in the admin but again in the domain list with the traffic its wrong... !
I googled but I only found someone mentioning the same issues on versions 7 and 8 ... Noone on version 9 ...