mod_php simply doesn't work if it is compiled with qt support. I found the -qt solution in the forums. Since I dont think this has been fixed yet, and has been around for somet time, maybe qt should be disabled by default in the ebuild.
Steps to Reproduce:
maybe you should give us more info to work with :)
`emerge info`, the error you're seeing, and config.log from the build directory at a minimum
Here is the thread, which contains the info you requested.
lu_zero says this is solved, so I'll close.
<lu_zero> with the latest glibc the problem should be solved
<shwag> lu_zero: the mod_php problem ?
# ldd /usr/lib/apache2-extramodules/libphp4.so |grep qt
libqt-mt.so.3 => /usr/qt/3/lib/libqt-mt.so.3 (0x6f09f000)
tested. mod_php 4.3.4-r4 works with USE=qt.