Delicious Bookmarks in Firefox 4 and 5

1. Start FF and navigate to “about:support”
2. Click “Open containing folder”
   
   
3. Navigate in the newly opened explorer window to subfolder “extensions\{2fa4ed95-0317-4c6a-a74c-5f3e3912c1f9}”:
   
   
4. Open install.rdf and find the line with “em:maxVersion”
   
   
5. Change the value to “4.0” (or "5.0")
   
   
6. Save the file and restart FF.