i just tried compiling with 5.2.5 on a PS.
I also had trouble with curl...
what I ended up having to do, is compile manually without using the script.
I had to change the configure options to compile php to add an explicit directory for curl since the configuration script will look elsewhere by default.
that directory should have your /lib and /include/curl in it.
I was finally able to successfully compile curl with a "make" and "make install"
following that, I continued to configure, make, make test, and make install
I don't know if adding an explicit directory to your curl configuration will help
I haven't gotten my php to work properly but at least curl compiled alright without missing things.
For cUrl, I used ./configure --with-ssl=/home/yourusername/yourphpinstalldirectory --with-zlib=/home/yourusername/yourphpinstalldirectory --with-libidn=/home/yourusername/yourphpinstalldirectory --enable-ipv6 --enable-cookies --enable-crypto-auth --prefix=/home/yourusername/yourphpinstalldirectory