Hi,
I have a similar problem. Have just started to install paypal shopping cart (1 item so far. Checking in various browsers is a nightmare! My site is http://www.jamesbartondesign.com .

1. IE, does not work at all. clicking on either "add to basket" or view basket" elicits to response at all (although the "pointing finger" does appear).

2. Firefox, OK but continue shopping does nothing.

3. Netscape, works perfectly.

4. Opera, nothing, maffi, zilch. Although I think it did work once, but it may be a figment of my imagination.

Anyone have a clue as to what is going on?