Also, why are you using the 32 bit version of Ubuntu? I'm not saying there aren't valid reasons to be using it, but I'm just curious if you have a 64 bit CPU, there is absolutely no reason to use the 32 bit version for mining.
If you have less than 4GB of RAM it's my understanding that a 64-bit OS will only serve to add overhead. I may be wrong about this as I haven't taken time to do much research. It's just what I've heard.