Please confirm what version of FreeBSD you are running. (uname -a)
Oh, and I take it you have run memtest86 (or similar) for an hour or so to rule out memory errors?
Did you follow the guide that you linked to? If so, then send a brick to the person that wrote it.
I don't know how you are going to get rid of that out-of-date, incorrectly compiled version of apache. If you still have the source directory, then "make uninstall" or "make deinstall" might do it.
Then you can reinstall the current version, correctly, using the port.
Code:
cd /usr/ports/www/apache22
make install clean
Let us know how it goes.