Empty delimiter

Hi, I have this mydebug message in the cache

[09-May-2012 19:43:06 UTC] PHP Warning:  strstr() [<a  href='function.strstr'>function.strstr</a>]: Empty delimiter in   /.............public_html/website.com/includes/functions/functions_email.php  on line 110

I've looked at similar posts for other line #s.
Have put back in original for admin/includes/languages/english/email_extras.php and /includes/functions/functions_email.php file
but still comes up with php warning in cache.

Any ideas?
(I dont know php)

I suspect you've changed the content of your language files and set the EMAIL_SPAM_DISCLAIMER or EMAIL_DISCLAIMER text to blank.

Are those files somewhere else to the ones that I replaced with originals in my post?
(hope so)
admin/includes/languages/english/email_extras.php
and
/includes/functions/functions_email.php file

eg. both of those files are originals from zen download and not modified anymore.

Yes.
/includes/languages/english/YOUR_TEMPLATE_NAME/email_extras.php

I might suggest you look into using the built-in Developers Toolkit to find these things in your files, or the search function on your PC if it can look through multiple PHP files for specified contents. A search for EMAIL_DISCLAIMER or even better: define('EMAIL_DISCLAIMER' shows where it's used.
http://www.zen-cart.com/content.php?80-how-do-i-find-out-what-files-to-edit
http://www.zen-cart.com/content.php?81-how-do-i-use-the-developers-toolkit

Thanks Drbyte,
I had used the developers toolkit to find those 2 files I mentioned, but hadnt realised theres the same file type in both admin/includes and includes.
What I had read lead me to think it was admin/ so didn't click there was another similarly named one to edit.
My oversight. Haven't confirmed yet that problem is gone, but pretty sure it should be sorted, thank you!