[cairo] Problem with rcairo 1.2.0 on Mac OSX 10.4.7

[Anne G]

I installed cairo 1.2.0 from source, ok I think

rcairo could not find cairo, so I had to add
PKG_CONFIG_PATH=/usr/local/lib/pkgconfig
LD_LIBRARY_PATH=/usr/local/lib
export PKG_CONFIG_PATH LD_LIBRARY_PATH
in /etc/profile

after that rcairo compiled, installed... but
when I run irb  and then
require 'cairo'
dyld: NSLinkModule() error
dyld: Symbol not found: _cairo_push_group
  Referenced from:
/opt/local/lib/ruby/site_ruby/1.8/powerpc-darwin8.3.0/cairo.bundle
  Expected in: flat namespace
Trace/BPT trap

What do I do now?