Enlightenment is quite happy to start up if you have another
window manager running (and hose up your X session if you
subsequently kill it). Haven't checked if this is fixed in
the latest DR, though.
Please contact the upstream maintainer (firstname.lastname@example.org) with info on this
bug. RHL comes with an old version of E, so this problem may be fixed in the
latest development release (0.16 etc.)