I get the same assertion failures and then segv, on a fresh 6.06 install. Here's what debian-bug reports about the package versions:
Package: xsane Version: 0.97-4ubuntu6 Severity: normal -- System Information: Debian Release: testing/unstable APT prefers dapper-updates APT policy: (500, 'dapper-updates'), (500, 'dapper-security'), (500, 'dapper') Architecture: i386 (i686) Shell: /bin/sh linked to /bin/bash Kernel: Linux 2.6.15-25-386 Locale: LANG=en_US.utf8, LC_CTYPE=en_US.utf8 (charmap=UTF-8) Versions of packages xsane depends on: ii libatk1.0-0 1.11.4-0ubuntu1 The ATK accessibility toolkit ii libc6 2.3.6-0ubuntu20 GNU C Library: Shared libraries an ii libcairo2 1.0.4-0ubuntu1 The Cairo 2D vector graphics libra ii libfontconfig1 2.3.2-1.1ubuntu12 generic font configuration library ii libgimp2.0 2.2.11-1ubuntu3.1 Libraries necessary to Run the GIM ii libglib2.0-0 2.10.3-0ubuntu1 The GLib library of C routines ii libgtk2.0-0 2.8.18-0ubuntu2 The GTK+ graphical user interface ii libieee1284-3 0.2.10-1 cross-platform library for paralle ii libjpeg62 6b-11 The Independent JPEG Group's JPEG ii libpango1.0-0 1.12.3-0ubuntu1 Layout and rendering of internatio ii libpng12-0 1.2.8rel-5 PNG library - runtime ii libsane 1.0.17-1ubuntu4 API library for scanners ii libtiff4 3.7.4-1ubuntu3.1 Tag Image File Format (TIFF) libra ii libusb-0.1-4 2:0.1.10a-22ubuntu1 userspace USB programming library ii libx11-6 2:1.0.0-0ubuntu9 X11 client-side library ii libxcursor1 1.1.5.2-0ubuntu4 X cursor management library ii libxext6 2:1.0.0-0ubuntu4 X11 miscellaneous extension librar ii libxfixes3 1:3.0.1.2-0ubuntu3 X11 miscellaneous 'fixes' extensio ii libxi6 2:1.0.0-0ubuntu3 X11 Input extension library ii libxinerama1 2:1.0.1-0ubuntu2 X11 Xinerama extension library ii libxrandr2 1:1.1.0.2-0ubuntu4 X11 RandR extension library ii libxrender1 1:0.9.0.2-0ubuntu2 X Rendering Extension client libra ii xsane-common 0.97-4ubuntu6 GTK+-based X11 frontend for SANE ( ii zlib1g 1:1.2.3-6ubuntu4 compression library - runtime Versions of packages xsane recommends: ii amaya [www- 8.5-1.3 Web Browser, HTML Editor and Testb ii elinks [www 0.10.6-1ubuntu3 advanced text-mode WWW browser ii firefox [ww 1.5.dfsg+1.5.0.4-0ubuntu6.06 lightweight web browser based on M ii galeon [www 2.0.1-1ubuntu2 GNOME web browser for advanced use ii links2 [www 2.1pre20-2 Web browser running in both graphi ii lynx [www-b 2.8.5-2ubuntu1 Text-mode WWW Browser ii w3-el-e21 [ 4.0pre.2001.10.27-19 Web browser for GNU Emacs 21 ii w3m [www-br 0.5.1-4ubuntu2 WWW browsable pager with excellent -- no debconf information -- SEGV on startup https://launchpad.net/bugs/37968 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs