http://bugs.winehq.org/show_bug.cgi?id=10360
--- Comment #21 from Austin English austinenglish@gmail.com 2008-02-07 11:37:07 --- (In reply to comment #20)
Most likely it's because the 32-bit version doesn't have a symlink.
On feisty, in today's git: $ ./configure --verbose | grep png
checking png.h usability... yes checking png.h presence... yes checking for png.h... yes checking for -lpng... libpng12.so.0