when i put the url "domain.com/?qa=blob&qa_blobid=17474948105245553660.pdf" in the browser directly, I am asked to download the PDF, but if I use it like you described only the following message is displayed: a plugin is needed to display the content.
any idea why this is not recognized?
how could this be automated when uploading the pdf?
might be acore hack necessary?
have you updated the embed plugin of noah?
here it seems like PDF is still not supported... maybe you could send him a pull request for your changes?