arredoannunci on "[Plugin: WooCommerce - excelling eCommerce] checkout-button no longer works"

hi could you help me?
I installed the latest version, (then I uninstalled it because it is not compatible)
I reinstalled the old version (all ok)
but the checkout-button no longer works
how can I fix it? please help me
the site is: http://www.riminikmzero.org
thank you very much
Gianluca

http://wordpress.org/extend/plugins/woocommerce/