Comment 285 for bug 401126

@Ken: try the dkms package in Matt Price's PPA, https://launchpad.net/~matt-price/+archive/mattprice . Simply install the package using synaptic/apt-get/..., and possibly reboot. This is just the latest Realtek driver release packaged as a dkms module, for which everything is done automatically. See bug #530275 for more info.

On a separate note, whether you choose to install 32- or 64-bit Ubuntu has no effect on this. In practice it might be marginally "safer" to stay on 32-bit Ubuntu, while you may obtain marginally better performance on 64-bit Ubuntu - it's your choice.