SOLVED!!
It turns out that this problem had to do with the installed gcc packages. When I compared the versions of the installed RPMs with a second YDL box, they were the same, but when I actually checked the file sizes of gcc they were different. So I downloaded a fresh copy from YDL's site and removed the installed RPM. When I went to install the fresh RPM, I got an error about conflicting with egcs-1.1.2-12e. So I removed egcs,
and was able to successfully install the fresh RPM. After this, I was able to build php.
The conflicting files with egcs were the same files I was trying to remove when I uninstalled gcc. I am assuming that when I originally installed YDL, and by selecting development tools, that YDL installed the gcc package and then installed the egcs package which overwrote gcc with the one that was included in egcs.