RPC communication between client and server running different GWT versions

[Gwencalon]

Greetings!

I'm trying to develop my first web application that uses GWT.

I'm using GWT 1.7.1 to develop the client, since I'd like to use
SmartGWT and it requires at least GWT 1.5.3.
However, my server is running JRE 1.4.2. Therefore, I can only use GWT
1.4.x.

To achieve this, I'm generating the client-side stuff with java 6 and
GWT 1.7.1. Then, I create my servlet with java 1.4 and GWT 1.4.62.
Unfortunately, this does not seem to be working. It works fine when I
have the server using the same GWT/Java version... but when I switch
to an older version it's not communicating.

I tried to check the release notes to see if something changed in RPC
communication, but apart from generics I couldn't find anything
relevant. Eitherway, I think I'll check version 1.5.3 for the client..
the closest version to the server's that fits my needs.

It may be some other issue, but if some one could tell me for sure
that it is/it is not possible to get/send data via RPC under such
conditions I'd be very grateful!

Thanks in advance!