Remove query strings from static resources – GD-Booster?

Hello,

one of my remaining page speed issues is concerning the message ‘Remove query strings from static resources’ on pingdom. Four of the listed items appear to be from GD Booster, served through MaxCDN. When I queried this with MaxCDN they said that they do not add query strings to what should be static content served through them – they suggested asking you if is something that the Booster cache plugin is doing?

admin creds and details to follow…