Nautilus closes instead of minimizing?

[rikona]

Nautilus "disappears" when minimized, and Colin has suggested that it
is closing instead of minimizing. I'd like to fix that. If I could
find a way to keep nautilus from closing when minimized, I may be able
to go back to using more native Ubuntu programs, which may get me back
to a more problem free system. 

Any ideas why it is closing instead of minimizing?

Thanks,

  rikona