I also have a problem with Proofing tools in MSO 2010. But it is a little bit different matter.
I bought some years ago MSO 2010 Home and Student in Russian edition. Now I have to re-install it, but my back up copy of the distributive was lost. I used the service for MSO Backup Download, where they asked my Product Key. Everywhere I could, I chose
"Russian" language, but the final link offers me to download English version, which doesn't have Russian Proofing tools. So ,the result is: I had bought Russian MSO 2010 and now I have to pay for Russian Spelling check (which due to currency staff costs me
as much as the MSO, when I bought it :) )