If you don't have 1946, you can only patch so far, until you get to the new add-ons that were included in 1946. So, get 1946 if you don't have it.
If you have 1946, you just need patch 4.08 and patch 4.09 and you'll be up to date, until patch 4.10 comes out.
Here's some more detailed info and links -
http://forums.ubi.com/eve/forums/a/t...3/m/9121094645