gnome-libs 1.4.2-6 still has broken icons on debian ppc sid

[Jack Howarth <howarth@bromo.msbb.uc.edu>]

Package: gnome-libs
Version: 1.4.2-6
   The new gnome-libs 1.4.2-6 build, like the last -5 build, exhibits
broken icons on debianc ppc sid in programs like evolution. Once again
this breakage is fixed by a local rebuild with Build-Depends libpng2-dev
added to debian/control. Can someone please explain to me why this was
removed and gnome-libs set adrift to build against whatever libpng#-dev
was last installed on the build machine. That approach seems quite insane
to me since I thought it was now agreed that gnome 1.4 was to be built
against libpng2, no? Can we get an NMU that restores the Build-Depends
to libpng2-dev for gnome-libs to see if this resolves the breakage. 
Thanks in advance.
                                 Jack