Réponse en anglais !
http://discussions.apple.com/thread.jspa?threadID=2316559
The Action Menu is the wee coggy thing that lives to the right of your Search window in the Toolbar. It's possible for the Action Menu to be greyed-out or missing altogether. If so, it's possible to get the Action Menu back by rebuilding the com.apple.Safari plist file.
Windows XP instructions
Windows Vista and 7 instructions
Notes
Windows XP instructions
(1) Quit Safari if you have it open.
(2) Go Start > My Computer.
(3) From the Tools menu, select Folder Options ...
(4) Click the View tab.
(5) Make sure Show hidden files and folders is selected.
(6) Click OK.
(7) In My Computer, open Local Disk C:
(8) Open the Documents and Settings folder.
(9) Open the folder with the name of the XP user account in which Safari has lost the Action Menu.
(10) Open the Application Data folder.
(11) Open the Apple Computer folder.
(12) Open the Preferences folder.
(13) Drag the com.apple.Safari plist file out onto the Desktop.
(14) Launch Safari. (This will rebuild the com.apple.Safari plist file and your Action Menu should be visible or no longer greyed-out.)
Windows Vista and 7 instructions
(1) Quit Safari if you have it open
(2) Go Start > Open.
(3) In the Organize menu, click Folder and Search Options.
(4) Click the View tab.
(5) Make sure that Show hidden files and folders is selected.
(6) Click OK.
(7) Go Start > Computer.
(8) In Computer open Local Disk C:
(9) Open the Users folder.
(10) Open the folder with the name of the Vista/7 user account in which Safari has lost the Action Menu.
(11) Open the AppData folder.
(12) Open the Roaming folder.
(13) Open the Apple Computer folder.
(14) Open the Preferences folder.
(15) Drag the com.apple.Safari plist file out onto the Desktop.
(16) Launch Safari. (This will rebuild the com.apple.Safari plist file and your Action Menu should be visible or no longer greyed-out.)
Notes
A missing or greyed-out Action Menu is a user-account specific issue, since each different Windows user account has its own com.apple.Safari plist file. When rebuilding the file, be sure to rebuild the one for the user account in which the problem is occurring.
