The current versions of libsigc++1.0 and libsigc++1.2 can't coexist. This means that you can't have both 1.x and 2.x versions of gtk--, gnome--, and glade--. But there's no good reason that they shouldn't be able to; it's just an artifact of the packaging. And there are plenty of good reasons to want both around. With a few minor changes to the 1.0 version, I was able to make them coexist.
The only negative is that the libsigc++1.0 no longer provides the virtual package name libsigc++ (and similarly for the -devel package). Since (in 9.1, and in current Cooker) 1.0 is in main and 1.2 is in contribs, possibly this should have been done the other way around (let 1.0 provide libsigc++ and instead change 1.2). But the difference should only be visible to users who (a) develop with Gtk-- 1.x but not 2.x, and (b) use non-Mandrake packages that depend on "libsigc++", I doubt anyone will complain. Fortunately, the relevant gtkmm, gnomemm, and glademm packages already know how to coexist, so this is the only change needed to develop Glade-- code for 1.2 and 2.0 on the same box. By the way, my first attempted upload failed, so please look at file libsigc++1.0-1.0.4-6mdk.src.rpm.2 for the correct package.
