My b2evolution Version: 1.10.x

I feel very silly having to post in here as I saw the 'tricky stuff' page that referenced this exact FAQ but I could not figure out what to do to fix the prob.

Here is where I stand: I downloaded version 2.4.2 today and uploaded to my server.
I followed instructions and did the website.com/blogs/install
I chmod basic_config.php and allowed the install to complete itself rather than the copy/paste option.
I renamed the .htaccess

I then used the online installation link to 'log-in' to the admin.

Thats when I got the following error:
Warning: Cannot modify header information - headers already sent by (output started at /web/sites/vicki/DOMAIN.net/blogs/inc/_core/model/dataobjects/_dataobjectcache.class.php:158) in /web/sites/vicki/DOMAIN.net/blogs/skins_adm/_html_header.inc.php on line 40

I read the FAQ on this error that was linked to from the 'tricky stuff' page and tried adding the "echo "foo";"statement into each of those two files (one at a time) then testing and neither worked ...
HOWEVER, I'm totally php illiterate and had NO idea WHERE to place it within the files!
I then deleted those two files and re-uploaded them in their original context.

Can you PLEASE assist a dumb blonde and tell me how I can get rid of this error?

thanks in advance for any assistance :)