I have the same problem with chromium, I don't know what the deal is. Even mozplugger doesn't fix it (and chrome/chromium will use mozilla plugins automagically these days. and they often work — flash does.)
mostly I try to quick view PDFs these days, but that's even worse than downloading the PDF if you have poor bandwidth.
Mozplugger does fix it as long as you use a recent version. Anything 1.13.1 or greater works (returning XEmbed = true to the browser is what fixed it I think).
I have been using xpdf to view PDFs in Chromium for quite a while now.