Check this out.
I had the same isue after installing subclipse in eclipse. I also had installed a few months ago RabitVCS plugin for nautilus.
The symptoms was all the same with the ones you mentioning plus that python was also mem leaking!
I removed rabitVCS cli, plugin and everything runs smooth now.
Ubuntu 12.04 amd64
Check this out.
I had the same isue after installing subclipse in eclipse.
I also had installed a few months ago RabitVCS plugin for nautilus.
The symptoms was all the same with the ones you mentioning plus that python was also mem leaking!
I removed rabitVCS cli, plugin and everything runs smooth now.
Ubuntu 12.04 amd64