PHP Installation/Upgrade problem

[EnderX]

I'm currently trying to upgrade a linux box running SusE 9 and Apache 2 (not sure what version) from PHP version 4.3.4 to PHP version 5.1.6.  I followed the instructions in the 'install' file that came packaged with the original download from php.net (to the best of my ability, at least).  I (after a fair amount of hunting) found the files that needed to be modified, and made the appropriate changes.  I swapped out the old php.ini file for a new one, created by making the appropriate adjustments to the php.ini-recommended file that came with the php 5 download so it matched the old one.  Finally, I restarted Apache.

Now, whenever I try to view any of my php pages, I get nothing.  Or almost nothing, rather.  As far as I can tell, any print or echo statement between the '<?php' tag and the first non-print statement works, but nothing else does.  Attempts to run php files with a non-print statement before anything else kick out blank pages (no source code), those which do have print statements before the first non-print will kick out everything up to that point, but not beyond.

And phpinfo() appears to still work, although it's telling me that I'm still running version 4.3.4.

I'm able to get my php files back because I archived the old php.ini file, so I was able to restore it.  But I'd really like to be able to upgrade.  Please note; I've never done this before; the system I'm working on is one I use at the office, and it had 4.3.4 on it when I was first hired.  I'm still new to Linux as well, so I'm probably missing something quite obvious simply because of that.  I would appreciate any help anyone here can give me, and will be quite willing to provide whatever extra data may be needed for someone to help me solve my problems.

Thanks in advance,
-EnderX