CentOs 4.5 Perfect Server ISPConfig install error

[sird]

Hey guys, I know this has been covered a bit but I couldn't see any responses for someone having trouble with CentOs 4.5.

I thought I had followed the perfect server guide word for word but I'm getting this error when trying to install ISPConfig.

** Apache requires an ANSI C Compiler, such as gcc.

======== Error Output for sanity check ========
cd ..; gcc  -DLINUX=22 -DMOD_SSL=208128 -DUSE_HSREGEX -DEAPI -DUSE_EXPAT -I./lib/expat-lite `./apaci`   -L/root/ispconfig/openssl/lib  -o helpers/dummy helpers/dummy.c   -lm  -lssl -lcrypto
============= End of Error Report =============

 Aborting!
./configure:Error: APACI failed
ERROR: Could not configure Apache
./compile: line 87: cd: /ISPConfig: No such file or directory
./setup2: line 851: cd: /ISPConfig: No such file or directory
mv: cannot stat `binaries/aps.tar.gz': No such file or directory
mv: cannot stat `binaries/spamassassin.tar.gz': No such file or directory
mv: cannot stat `binaries/uudeview.tar.gz': No such file or directory
mv: cannot stat `binaries/clamav.tar.gz': No such file or directory
mv: cannot stat `binaries/cronolog': No such file or directory
mv: cannot stat `binaries/cronosplit': No such file or directory
mv: cannot stat `binaries/ispconfig_tcpserver': No such file or directory
mv: cannot stat `binaries/zip': No such file or directory
mv: cannot stat `binaries/unzip': No such file or directory
tar: spamassassin.tar.gz: Cannot open: No such file or directory
tar: Error is not recoverable: exiting now
tar: Child returned status 2
tar: Error exit delayed from previous errors
mv: cannot stat `spamassassin': No such file or directory
tar: uudeview.tar.gz: Cannot open: No such file or directory
tar: Error is not recoverable: exiting now
tar: Child returned status 2
tar: Error exit delayed from previous errors
mv: cannot stat `uudeview': No such file or directory
tar: clamav.tar.gz: Cannot open: No such file or directory
tar: Error is not recoverable: exiting now
tar: Child returned status 2
tar: Error exit delayed from previous errors
mv: cannot stat `clamav': No such file or directory
tar: aps.tar.gz: Cannot open: No such file or directory
tar: Error is not recoverable: exiting now
tar: Child returned status 2
tar: Error exit delayed from previous errors
./setup2: line 873: ispconfig_tmp/php/bin/php: No such file or directory
ERROR: The PHP binary coming with ISPConfig does not work properly on your system! The installation routine stops here!

Does anyone know what I've done wrong or what I can do to fix it?
Thanks,
Allan.