Robert_Charlton - 6:02 pm on Jul 5, 2012 (gmt 0)
We use to add press release from the official source and use to provide free downloads which was available for free on the internet.
This certainly sounds like duplicate content. What's not clear is what in particular you might have done that involved "techniques that are outside Google's Webmaster Guidelines".
From the Duplicate Content section of the guidelines [support.google.com...] the following jumps out at me...
(my emphasis added)...
Duplicate content on a site is not grounds for action on that site unless it appears that the intent of the duplicate content is to be deceptive and manipulate search engine results.
What proportion of your 45K articles involve dupe material?