Hi, thank you for contacting JustAnswer.com. My name is Russell. I will do my best to provide the right answer to your question.
I presume you have observed the DADF feeding to be slow, when scanning or when photocopying, since those are the operations that use the DADF.
Or is it only scanning, to a computer, that is going slowly?
I advise you to test, with a photocopy or two of documents fed and scanned for photocopying through the DADF, to see whether the slow feeding only happens with scanning to a computer... if that's how it is, then you may have a slow-communication problem, or a lack of scanning buffering, or similar issue.
You say the feeding speed is 'unusual'... please explain, if there is anything more in the way of details to mention.