I think the amount of data you get on sudo apt-get update using the pre-configured apt repositories is HUGE - and IMHO 256 MB is barely enough to get reasonable performance in the first place, though the flash storage is more critical for the update and install. One option is to simply get the .deb file and install it manually with either dpkg (command-line installer) or gdebi (GUI installer) started from the LXTerminal window.

Hope that helps!
Krishna