Yes - it's only for 4.3.3 and, if you haven't saved your blobs or you don't know what I mean by that, there's no way you can Jailbreak, because the current iOS is 4.3.5 and there's no JB solution for that.
So, you'll probably have to wait until a JB is available for iOS5 because it's unlikely any further iOS4 JBs will be available.
Tim