I'm working locally for now, but I assume (oh jeez!) that it would be the same in a live scenario.
If I add a product to cart whilst testing this project, let's say the URL is:
http://localhost/tammyssweetstems/product.php?pID=12
...and I then view cart on another project that uses the same cart name:
http://localhost/thevaultartscentre/view_basket.php
...the product from the other project is in the cart. :S
NJ