PDF::API2 suddenly broken

My trusty PDF::API2 which has worked perfectly for years has suddenly  
ceased to function. This minimal script:

$page = $pdf_out->page;
$page->mediabox(595, 842);
$page->gfx;
#$xo = $pdf_out->importPageIntoForm($pdf_in, 1);
#$gfx->formimage($xo, 0, 0, 1);

trips up at the line '$page->gfx' with the error 'Undefined subroutine  
&Compress::Zlib::compress called at /Library/Perl/5.8.8/PDF/API2/ 
Content.pm line 102.'

But 'Compress' is there and 'Zlib.pm' in that folder; and Zlib has a  
subroutine named 'compress'. So what can be possibly be wrong here? "/ 
Library/Perl/5.8.8/' is in @INC, so "/Library/Perl/5.8.8/Compress/"  
should be found, should it not?

If the next line is included ($xo = etc.) the error message changes  
to: 'Can't call method "infilt" on an undefined value at /Library/Perl/ 
5.8.8/PDF/API2/Util.pm line 667.'

The only thing that has changed in recent days is a security update  
(Mac OSX 10.5.6 -- Intel MacPro) which I think was mostly to do with a  
loophole in Safari -- and I doubt that had anything to do with  
"Compress::Zlib".

I would be most grateful for any suggestions what to do next,

Alan Fry