xlibs installation problem

[Ruchira Datta <datta@math.berkeley.edu>]

I am a user of the Debian potato installation.  I am perfectly happy with
potato and in particular, I do not want to upgrade wholesale to woody, until
it is actually released.  Generally, if there are any packages I particularly
want from woody or sid, I install them on a case-by-case basis.

In particular, I would like to install libwxgtk2.2 from sid, which depends on
xlibs(>=4.0.1-11).  The xlibs package depends on:

xfree86-common(>>4.0)
libc6(>=2.2.1)
xlibs(>=4.0.1-11)

all of which I have installed (except, of course, for xlibs(>=4.0.1-11)).
If this is supposed to mean that I should upgrade to a lower version such
as xlibs 4.0.1-11 before upgrading to the version in woody, xlibs 4.0.2-1,
then I have no way of doing that; the version of xlibs in woody is the
earliest version available (it replaces xlib6g, which I have from potato).

Anyway, when I try to install xlibs, I get the following:

# dpkg -iGREB xlibs_4.0.2-1_i386.deb
dpkg: considering removing xlib6g in favour of xlibs ...
dpkg: yes, will remove xlib6g in favour of xlibs.
dpkg: /home/wichert/debian/dpkg-1.6.15/main/archives.c:601: check_conflict: Assertion `fixbyrm->clientdata->istobe == itb_normal' failed.
Aborted

I have no idea what this means.  Can anyone help me?  I can provide more
info on what versions of what packages I have installed.

Thanks,

Ruchira Datta
datta@math.berkeley.edu