...then you know what it's about. After our 4.0.5 update we're a little paranoid with checking certificates! You should check that the Modulus is the same, it's signed by Entrust and the Serial number match. If so you can happily click on 'Trust' and be on your merry way.
If you don't see this or the details are different it means you're not speaking to our servers...and you should be worried.