[Koha-win32] Problem editing tag subfields: ver. 2.2.4

[Bob Treitman]

I've managed to set up Koha 2.2.4 for Windows and have a few questions. Here's the first one.

Am I allowed to edit the default framework? Or am I trying something I shouldn't? Here's what is happening:

1. I navigate to Parameters-Biblio Framework. The page reads: 
Biblio framework
framework name, then go to MARC biblio to set MARC editor parameters

(Aside: Is there supposed to be something in front of that second sentence fragment?)

2. I click the MARC Structure button to get to 
MARC tag structure admin for default MARC framework
 
3. I click on the first subfields link (green box) and get to 
MARC subfield structure admin for 010 (framework) 
where it says "You can edit subfields or add a new one by clicking on edit." I don't see the word "Edit" anywhere though assume that the open folder with the arrow on it at the bottom-left of the screen is the Edit hyperlink. But when I click on that folder, it returns an error message: 
Server error! 
The server encountered an internal error and was  unable to complete your request.       
Error message:     
Premature end of script headers: marc_subfields_structure.pl       
If you think this is a server error, please contact the webmaster.    
Error 500    intranet
03/31/06 15:01:35
Apache/2.0.54 (Win32)

The URL that gives this error is:
http://intranet/cgi-bin/koha/admin/marc_subfields_structure.pl?op=add_form&tagfield=020&frameworkcode=

Did I install something wrong? Thanks for any guidance you can provide. 
Details from the About screen:

Server information
Koha version2.2.4
OS version Microsoft Windows XP [Version 5.1.2600]
Perl version5.008007
MySQL versionmysql Ver 12.22 Distrib 4.0.26, for Win32 (ia32)
Apache version

(Aside: For some reason, the About screen doesn't display the Apache Version.)

Thanks, 
Bob Treitman