lucy24 - 12:44 am on Feb 21, 2013 (gmt 0)
There is absolutely no way that anyone reading your post can provide any more information. Only you can do that. The two most obvious places to look are:
--your site's htaccess file
--your in-progress headers using a utility such as Firefox's Live Headers
If people request the wrong form of a page name, then it is correct to redirect them, since the alternative leads to Duplicate Content.
If your site itself links to the wrong form of a page name, you need to fix the code.
If you are using a cms that auto-generates links in the wrong form and then redirects to the right form, get a different cms.