which not working as expected

Hello.

Consider the following magic words:

# ls `which adduser`
ls: /usr/sbin/adduser: No such file or directory
#

Hmmm...
Then:
# ls /usr/sbin/adduser
/usr/sbin/adduser
#

Now what?
Unforunately this little sniippet is used in my debian woody server's mysql pre install script. Which means I can't upgrade or remove it.

What is causing it?
Debian woody running bash 2.05a-11.

What does this show?

echo `which adduser` | od -c

0000000 033 ] 0 ; w a l l : / r o o t \a /
0000020 u s r / s b i n / a d d u s e r
0000040 \n
0000041

This was a real eye-opener.
khm... I've done some prompt magic. Disabling that the whole thing was fixed

Thank you very much indeed.