Upgrading from Unity Pro 4.2.0f4 to 4.3.4

Hello, everybody. I have a doubt concerning the update of Unity Pro.

I work in an University, so I have it licensed for education. I have the 4.2.0f4 license, and would like to upgrade it to the 4.3.4, but Im not sure I can do that and keep my serial number. So that´s my question:

Is my serial number valid for the 4.3.4 version, or would I need to purchase another one?

Licenses are usually bought for a main version, so your license should be valid for all iterations of version 4. But I can not guarantee anything and you should rather ask unity support about this: support@unity3d.com. Put something about licensing in the subject of the email and they get back to you faster.