Latest versions of Wuala also show this message but for different reason. Wuala installer will install 32-bit Java VM if it is not present on the system. Sometime later, the 32-bit Java VM gets uninstalled for some reason, perhaps when some update removes older insecure VM and replaces it with new one, which happens to be 64-bit. Wuala then stops working.
The solution is to install both 32-bit and 64-bit Java VM side by side by downloading offline 32-bit installer from java.com. This is a supported configuration, although it's not the default. Reinstalling Wuala does the job too as it triggers installation of the right Java VM.