Need help in debugging GNU-sync-vc crash with 21.4.19

Like I've muttered a few times already, one of the remaining blockers for starting to consider pushing the GNU-synced vc package from unsupported/scop/vc to the packages tree is that it causes lots of crashing when opening vc-controlled files. Debugging that is unfortunately beyond me, so help is needed. Here's the setup for the reproducer: The binary package built with XEmacs 21.4.19 from what's currently in unsupported/scop/vc in CVS is available at http://koti.welho.com/vskytta/xemacs/new-vc/vc-0.01-pkg.tar.gz Minimal tarball containing one Subversion controlled file: http://koti.welho.com/vskytta/xemacs/new-vc/svndir.tar.gz Install the above vc package, modify ~/.xemacs/init.el and add "(require 'vc-hooks)" there, unpack the svndir tarball somewhere. Now, try to open the SVN controlled file from inside the tarball -> for me, XEmacs crashes _almost_ always. When it doesn't, it displays a random error message. Sometimes (*very* rare), it opens the file successfully. This happens with other vc backends besides svn too, although the success rate might be a bit higher with eg. cvs. I won't bother including backtraces or error messages because they seem to be different on every run. I have discovered that if I remove auto-autoloads.elc from the above installed vc package (but leave auto-autoloads.el in), XEmacs never crashes. No other ideas :( My Installation file: http://koti.welho.com/vskytta/xemacs/new-vc/Installation.txt (Currently running FC5test[23] on x86_64 and XEmacs 21.4.19 built with gcc 4.1.0 and using neXtaw, but I've reproduced with a variety of XEmacs 21.4.x versions, some using Xaw3d, i386 and x86_64, built with gcc's 3.4.x and 4.0 too.)