as it is very unlikely that any PDF document on a website would require version 11.0 of Adobe Reader to open it.
Safari is the default PDF reader on the Mac, so let's go back to basics to see if this can be sorted out.
Uninstall Adobe Reader from your Mac, remove all the Adobe Reader preferences from your Home folder > Library > Preferences. (Just drag them on to the desktop)
Now go to the Library that is at the root of the Hard Drive and find Internet Plug-ins.
(again, drag them to the desktop)
Now go back to the site that requires V11.0, would be nice if you were to tell us what the site is, and see what happens when you try to open a PDF file.
Where are you trying to download V11 of Adobe Reader from?
Go to www.adobe.com and click on the downloads button. Choose Adobe Reader and try again, but only if you really need to have it installed.
I have recently been told by 2 websites where I open PDF pages to download version Xl (11.0) of Adobe Reader. This was done but I still can't access the pages.
I have Mac OS X Version 10.6.8. A warning screen tells me that "Adbe Rdr 11000_en_US. not recognized". On the Adobe site I tried to change the country from U.S.A to New Zealand.
What do I need to do ?