Hi,
It depends apon how the web site has been coded.... since it works
when you turn on compatiblity view... this suggests that the web site
uses UA sniffing and seves different code for what 'it' thinks is the
correct browser.
links to pdf documents in search results may be using redirects.....
check that you are accepting the default IE security zone settings...
Tools>Internet Options, Security tab, click "Reset all zones to
default".
do you have the address of a web site that shows this behavior?
Possibly, the Adobe Reader uses an IE Addon - "PDF Link Helper" to
determine how to open files with a PDF extension... perhaps you have
disabled that Addon or its behaviour in IE9 standards mode is different,
although there have not been any similar questions
to yours.
I recommend that you do not use the ActiveX adobe pdf reader to open
PDF files in the web browser. You configure Adobe Reader to not use the
browser to open pdf files by...
Start>Search.... Adobe Reader
select Edit>Preferences>Internet, uncheck "Use browser todispay pdf"
try the workaround above (viz turn off opening pdf documents in the
browser) and see if the issue persists or post back with a link to a web
site that has the problem.
Regards.