I encountered this error while congiuring Zen-Cart today.
I struggled hard to find the solution on forums. The last thing i got from w3School was to change the behaviour url address link to absolute from relative and it is woring ok now.
1. I copied the csshover.htc file in the same directory as the page calling it
And
2. I changed the :
behavior: url(/include/csshover.htc);
TO behavior: url(csshover.htc);
Hence it need not to go relative path. And is working ok now. Hope would help someone.
Thanks.