The zombie processes are a bug in mono. If you upgrade to mono 1.1.8.3
or 1.1.9 these should go away. (I also think we worked around a lot of
them in 0.1.0 but I might be wrong about that.)
That won't really fix the memory problem though for a singular instance.
The index helper process can end up taking a large amount of memory, but it's a short-lived process