My problem was actually with mod_dav (which referred me here). Since they took the time to point people here, I thought I'd go ahead and add my two cents worth and expand on the above since it obviously affects PHP as well. I am running Fedora Core 3, Apache 2.0.53, & PHP 5.03. Apache and PHP were built from source.
The first suggestion in section 13 above was close, but not exactly what I needed. jimsteele's suggestion would have worked, but you would have to do it every time you use APXS. What I did was copy these lines:
my $CFG_CFLAGS_SHLIB = '-fpic -DSHARED_MODULE';
my $CFG_LD_SHLIB = 'gcc';
my $CFG_LDFLAGS_SHLIB = q(-shared);
and pasted them in the configuration section of my apxs file. Worked like a champ.