I am using an include file by doing:
<!--#include virtual="/includes/leftNav.shtml"-->
I changed the include file, and the changes are not picked up. I'm guessing that they will be with a server restart; is it possible to have the changes picked up w/o a restart?
The root level page is possibly cached, either by the server itself or the browser. Adding a query string to the request (i.e.: http://mysite.com/index.shtml?0827091630) might get you a new copy of your doc.
Server-side includes don't need a server restart. They take immediate effect. If they don't work, it probably means that your Apache server is not configured to support server-side includes at all, or not for the type of file you are trying them on.
There tends to be caching issues for any static content type extensions it really should work with just a ctrl+F5