[CentOS] Probably a bad set-up but which one?

I am having a problem that I assume is a set-up problem but I don't know 
which area to look at to fix it. Hopefully someone here can point me in 
the right direction.

I can't get the simple Perl "Hello World" script to work.

Oh, it does print "Hello World" OK but it also prints the "Content" line 
as text rather than using it as a directive.

Two different servers (both CentOs 5) and both IE and Firefox are doing 
the same thing.

I first tried a JavaScript program (free online shopping cart) and it 
wouldn't work properly. So, I changed to CGI and can't get it working OK 
either.

What does work: CGI/Perl visitor count program. Count.log and main.log 
exist and get updated and display the updated count in the browser OK.

What doesn't work: "content" line is seen as text. I can't create a file 
using CGI. I can append to one but I can't create one. I have tried a 
CGI shopping cart (Commerce) which has an install script. It displays 
the first page OK but when I click on "Continue" I get the same page 
again. The script says clicking on "Continue" should submit a form 
(Post) with a name of "step2. An IF statement should see that name and 
go to the step2 subroutine. It doesn't. It falls through to the ELSE and 
displays the same page. A Print command shows the name is blank after 
the click. The browser knows about the form because a refresh tells me 
about the stale form data.

I have the AddHandler lines and the ExCGI option in my http config. I 
have checked that all spelling and cases are OK. Carp Fatal to Browser 
is not showing any errors. Server error log doesn't seem unhappy either. 
I have done some searching in news groups and Deja, ooops sorry, Google 
and didn't find anything that helped.

Where do I look next?