Luciano -- are you experiencing this problem with any other PDFs? How many? I took a quick look at your back-issues, and it seems that a number of PDFs are behaving properly. You may just have to reupload that one, or at the very least check what it looks like on the server side.
Katrin -- unfortunately, we don't communicate privately unless it's a paid consultation -- if you are interested in that, please see our rates at http://pkp.sfu.ca/commercial
Everyone else -- this thread revolves around two separate problems. Luciano's problem is that at least one PDF is appearing garbled/is being mihandled when viewed, whereas as far as I can tell everyone else is experiencing a problem with the way PDFs are being viewed. Please note that seeing a note similar to what jaik_70 wrote ("This PDF file you selected should load here ... etc.") is normal
: users see this if they don't have a PDF plugin installed in their browser. If you are running into this problem and you are absolutely sure that your browser can display inline PDFs -- that is, if you've tested it with another PDF page, and it works fine -- please let us know, and include a link to your site, so we can also test.
I've also added a feature request for an additional direct-link-to-PDF configuration option to our bug tracker, here: http://pkp.sfu.ca/bugzilla/show_bug.cgi?id=6565
. Please feel free to CC yourself to the report for future updates.