I have the problem that, when I select a product and press ' add to cart' the shopping cart remains empty and I'm rederected to an emtpy shopping cart. Looks like this problem but not only with child products:
When I switch to a default template the problem is gone. What's really strange: when I put back a back-up the problem is still there.
It happens on the real site www.wilbert.nl and on my local test-site