I take it that you are non-exclusive?
Basically if your non-exclusive then all your clips are on getty but only a select number of people can view it. In a nut shell - they are available through Premium Access where they sell for pennies. There is nothing you can do to stop this except to delete your port - but this will be off istock too.
If your exclusive then your clips should be in the main collection (ie expensive clips) but also Premium Access. Lots of exclusives are finding that there main sales are drying up because of Premium Access.
Premium access is where Getty sells a membership to the big buyers for huge discounts. We don't see any money of the membership fee.
It's a pretty sorry affair really