[Mediawiki-l] Premature end of script headers in index.php??

[BruceMount at aol.com]

I'm sorry if this is a newbie question.  Last week I set up a wiki for the 
first time and everything worked for several days.  I was able to edit pages, 
etc.  During the work week I did not use the wiki and it's unlikely anyone else 
did, unless someone just tripped over it. Yesterday, my site was down and I 
got the following server error:

"Premature end of script headers: /home/xxxxx/public_html/wiki/index.php 
Failed loading"

...when I try to go to the home page.  The browser gives a "500 server error" 
message.  Given that I have not touched the site in days, does anyone have 
any ideas what would cause this error in index.php?

Thanks,

--Bruce