No problem with pango 1.20. With pango 1.26, I get:

make[5]: Entering directory `/mnt/hda3/tmp/deb-paketoj/opt/20100305-nova-gtk/06-pango/dsc/deb/b/pango/opentype'
  CC     libharfbuzz_la-hb-blob.lo
  CC     libharfbuzz_la-hb-buffer.lo
  CXX    libharfbuzz_la-hb-font.lo
In file included from hb-open-file-private.hh:30,
                 from hb-font.cc:31:
hb-open-type-private.hh:221: error: parse error before `__attribute__'
hb-open-type-private.hh: In function `bool _hb_sanitize_edit(...)':
hb-open-type-private.hh:225: error: syntax error before `->' token
hb-open-type-private.hh:405: error: explicit specialization in non-namespace
   scope `bool _hb_sanitize_edit(...)'
hb-open-type-private.hh:405: error: template-argument `
   _hb_sanitize_edit(...)::Tag' uses local type `_hb_sanitize_edit(...)::Tag'
hb-open-type-private.hh:405: error: can't make `get' into a method -- not in a
   class
hb-open-type-private.hh:492: error: type specifier omitted for parameter `
   GenericOffsetTo<OffsetType, Type>'
hb-open-type-private.hh:492: error: parse error before `)' token
hb-open-type-private.hh:492: error: `const Type& operator+(...)' must have an
   argument of class or enumerated type
hb-open-type-private.hh:492: error: `const Type& operator+(...)' must take
   either one or two arguments
hb-open-type-private.hh: In function `const Type& operator+(...)':
hb-open-type-private.hh:495: error: template argument is required for `
   operator+(...)::OffsetTo<Type>'
hb-open-type-private.hh:495: error: parse error before `<' token
hb-open-type-private.hh:498: error: template argument is required for `
   operator+(...)::LongOffsetTo<Type>'
hb-open-type-private.hh:498: error: parse error before `<' token
hb-open-type-private.hh:507: error: template argument is required for `
   operator+(...)::GenericArrayOf<LenType, Type>'
hb-open-type-private.hh:509: error: can't make `operator[]' into a method --
   not in a class
hb-open-type-private.hh:514: error: can't make `get_size' into a method -- not
   in a class
hb-open-type-private.hh:516: error: can't make `sanitize' into a method -- not
   in a class
hb-open-type-private.hh:530: error: can't make `sanitize' into a method -- not
   in a class
hb-open-type-private.hh:539: error: can't make `sanitize' into a method -- not
   in a class
hb-open-type-private.hh:548: error: can't make `sanitize' into a method -- not
   in a class
hb-open-type-private.hh:558: confused by earlier errors, bailing out
make[5]: *** [libharfbuzz_la-hb-font.lo] Error 1