Proxy settings for Adobe Digital Editions

I'm attempting to use Overdrive for iOS as a elibrary reader for a school library. Books won't download through the proxy server (ok when going through the upstream proxy) I've searched everywhere for exceptions and extensions to add to bypass with no luck. Please help as i'm really stuck. The error message i'm getting when attemoting open up a book with Overdrive is:

ACS4 Authorisation

Error:2004

Adobe Request

Error:E_ADEPT_XML_SYNTAX-

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