libltdl3 not installable

["Thomas H. George" <lists@tomgeorge.info>]

I am trying to install iscan in Squeeze but it depends on libltdl3 which
is not installable.  A search of the Debian package lists finds libltdl3
in Lenny and as a virtual package libltdl for Squeeze.  I installed
libltdl and ran apt-get -f install which again reported libltdl3 not
installable and removed the partially installed package iscan.

Is there any way around this?

Note: After a day of unsuccessful attempts to find the cause of the
segfault when running xscan - see posts to the debian-user and
sane-devel lists - I have given up.  I can run my Epson scanner from a
terminal with scanimage and open the resulting foo.pnm file with gimp
but without xscan or xscanimage gimp cannot use the scanner directly.

Tom