There are a couple things you could try.
1. Try defaulting all of your classes within MW3.
2. Unlink then relink your Gamertag/SEN ID within ELITE.
3. Clear the cookies/cache/history within your browser. Just in case you're unsure of how to clear your cache/cookies/history:
http://goo.gl/icX1l (IE and Firefox)
http://goo.gl/kRni7 (Google Chrome)
4. After all of the above, play a few matches of MW3 then check ELITE to see if your changes have taken place.