Unwanted Session ID being added to URL's
I am setting up a navigation menu on a new site im working on that is inking to *.php files. I have not added any php Session ID info to but for some reason when i click a link sometimes this will be appended.
Here is my navigation menu:
I presume it must be some server issue but i dont know what i should be looking into about this? It seems to be very random, most of the time it doesn't add the session id to the URL's but every now and then it appears.
<li><a href="../online-farm/">ONLINE FARM</a></li>
<li><a href="../grown-locally/">GROWN LOCALLY</a></li>
<li><a href="../organic-food/">ORGANIC FOOD</a></li>
Anyone know what might be going on here?