I investigated this further after realizing that on my other machine `/usr/share/doc/libpango1.0-0' is a symlink to `libpango1.0-common'.
I first tried to re-install the old versions:
$ sudo dpkg -i libpango1.0-0_1.28.3-1+squeeze2_i386.deb
libpango1.0-common_1.28.3-1+squeeze2_all.deb
[...]
$ file /usr/share/doc/libpango*
/usr/share/doc/libpango-perl: directory
/usr/share/doc/libpango1.0-0: directory
/usr/share/doc/libpango1.0-common: directory
/usr/share/doc/libpangomm-1.4-1: directory
$
I then removed the directory and re-installed:
signature.asc
Description: This is a digitally signed message part

