3rd try. *sigh*...

chrome_frame/bho.rgs

 HKLM {
   NoRemove SOFTWARE {
     NoRemove Classes {
       ChromeFrame.Bho.1 = s 'Bho Class' {
         CLSID = s '{ECB3C477-1A0A-44bd-BB57-78F9EFE34FA7}'
       }
       ChromeFrame.Bho = s 'ChromeFrame BHO' {
         CLSID = s '{ECB3C477-1A0A-44bd-BB57-78F9EFE34FA7}'
         CurVer = s 'ChromeFrame.Bho.1'
       }
       NoRemove CLSID {
         ForceRemove {ECB3C477-1A0A-44bd-BB57-78F9EFE34FA7} = s 'ChromeFrame BHO' {
           ProgID = s 'ChromeFrame.Bho.1'
           VersionIndependentProgID = s 'ChromeFrame.Bho'
           InprocServer32 = s '%MODULE%' {
             val ThreadingModel = s 'Apartment'
           }
           'TypeLib' = s '{6F2664E1-FF6E-488A-BCD1-F4CA6001DFCC}'
+          'Implemented Categories' {
+            {31CAF6E4-D6AA-4090-A050-A5AC8972E9EF}
+          }
         }
       }
     }
   }
 }