Sharepoint searched and opened document are in read mode only and the edit button does not appear
This issue makes me crazy for about one week... then today I fixed the problem! It's not a sharepoint configuration problem, but an internet explorer 7 security issue!
Off course! Why I did not think for this early?!?
So, to fix it add the following registry key to your windows registry:
HKEY_CURRENT_USER\Software\Microsoft\Office\12.0\Common\Internet\OpenDocumentsReadWriteWhileBrowsing = 1
It is the correct key if you have Microsoft Office 2007, if you have a different Office installation take a look to the following document where is indicated the same registry key for Office 2003 and Office XP.
http://support.microsoft.com/kb/870853/en-us