Bad, naughty Acrobat! Get OFF Safari!When you install Acrobat Reader on MacOS X (regrettably necessary for the odd awkward pdf) it will take over from Preview in Safari, opening pdfs clicked on on the web for you. Which would be fine, except that it takes about a minute to start up and looks totally wrong in Safari. It turns out that this unpleasant, anti-social behaviour can be remedied; open the real Acrobat Reader, go to preferences, and uncheck the 'open in browser' thing. Then restart Safari.
Really, Adobe would have been better not to have it do this in the first place. I can't imagine anyone wanting this behaviour; Preview is better in almost every case. I'd say it's earned them a fair bit of ill-will, and I doubt many people have figured out how to disable it.