Did you get all your RPMs from RedHat distribution sites?

Your error log should be /var/log/httpd/errors.

Take a careful look at your directory tree.  I don't off the top of my head
remember, but I believe that you need both the executable bit on the script
set and the ExecCGI directive active for the directory the php script is in.
Supposedly, you don't need both but it works if you have both.

Using RPMs exclusively from RedHat, or in the absense of those direct from
the site of the package in question, I didn't have any problems, and I did
have support for MySQL in my PHP4 installation.  This worked for me on RH7.2
and 7.3, so RH has probably changed the option since 7.0.
  It could be that by updating your packages, or doing a CD upgrade you
could get to where you should be. Dot-zero relases are notorious, so I
wouldn't upgrade to 8.0, but 7.3 might be worth while.

The default configuration for up2date now disables kernel upgrades, but I've
never had a problem with them.  Then again, I have been very deliberate to
work entirely within the RedHat paradigm and not screw around with things
like modules or file locations.  Make a boot disk!  You also don't have to
update everything with up2date - you can either request a specific package,
or you can go to the rhn web site, browse around, and pick stuff to be
automatically installed next time your system connects.  Given the
difficulty of getting updates for Mandrake unless you subscribe to their
service, which I believe is much more expensive, I found the $60 annual fee
for guaranteed connections on rhn worth while, and I may convert all my
Mandrake boxes to RedHat.