completion while su-ing in eshell

[lorint . hendschel]

Hi,

In eshell, when I su to root or another user, tab completion acts
strange: nothing is echoed except the tab, yet completion works, i.e.
if I hit enter after this:

# ls G______  

, I can actually see the contents of directory GNUstep.  In addition,
M-p and M-n to browse through the command history do not work.

Google shows that someone posted the same question 1 year ago, but
there was no answer.

I use Emacs 21.2-1, eshell 2.4.2 on Debian/Gnu/Linux Woody.

Thanks for any hint.

Lorint