My suggestion to all here is to open a terminal screen and run the program with:

/opt/whatsapp/launch.sh

That way, when you want to quit whatsapp, just go to the terminal and hit CTRL-C and type:

exit

No more memory issues... I remember having 7 different java sessions and using the kill command is just too much typing... Hope this tip proves useful to all in this thread.

Ohhh! If you run whatsapp with:

/opt/whatsapp/launch.sh~

You will find the output a little different... :P