Issues on Creating New Accounts ? (Adcenter)

I recently have issues (accounts getting banned without impressions) with new accounts on adcenter. I would like to know if Adcenter gurus here have similar problems ?

I certainly take some actions to hide any footprints such as :
-Use Virtual Box
-Use Socks - Proxifier
-Use CCleaner

Any ideas ?

what fundin source r u using ?