recompiling php -> apache doesn't start anymore and nowhere are errors...

hi guys! i runned apache v1.3.14 with php 3.0.18 and php 4.0.4pl1 . i justed upgraded to apache v1.3.20. everything worked well with the old - already installed - php-modules. now i wanted to update php v4.0.4pl1 to v4.0.6. it compiled well and after a 'make install' my apache doesn't want to run anymore. if i re-install the old php4-module (cp libphp4.so.backup libphp4.so) everything works well again. the problem is that there is no error-output. nothing written to console and nothing in the error-logfile :-( httpd -t returns 'syntax ok' and 'apachectl start' writes 'httpd started' but this isn't true. there is not even one httpd-process... i don't have any idea how i can figure out where/what the problem is. any ideas? thank you :-) - blinky