This is final hurdle for me to be 100% happy with Gtranslate

In my website I have some parts or modules I would like to exclude from translation. Reason?
These modules are dynamic and they will get to heavy(cache) for my site thats why I want to exclude them.
1) Forum
2) RSS Feeds
I already tried to put in this code class="notranslate" into Module Class Suffix area in the administrator panel for each module. Unfortunately it didn't work.
Any suggestions from anyone will be appreciated.
Regards
Nikolas