revert add problem

[Neal Becker]

According to help, I should be able to use revert to undo add, but it
doesn't seem to work:

>hg status ./doc
A doc/.#SConscript
A doc/design_document.lyx
? doc/#SConscript#
> hg revert ./doc/#SConscript
doc/#SConscript: No such file in rev 17ed02bf072a
> hg status ./doc
A doc/.#SConscript
A doc/design_document.lyx
? doc/#SConscript#

Perhaps it's because I just added the dir 'doc' and didn't commit anything
yet?