WooCommerce – Can’t remove items from cart

I can’t remove any item from a cart clicking on the red x button. There’s no error and I don’t even use any caching plugins. The only possible solution is to remove the WooCommerce session cookie. Please, can you help me to solve this problem?

Cart

WooCommerce session cookie – wp_woocommerce_session_{#hash}

Some specs

• WooCommerce ver. 2.5.5
• WordPress ver. 2.5.2
• No caching/minify plugins
• WordPress theme Optimizer 0.4.1

WooCommerce plugins used (disabling them didn’t help)

• YITH WooCommerce Uploads
• YITH WooCommerce Cart Messages
• WooCommerce Advanced Product Quantities
• WooCommerce – All in One SEO Pack
• WC Simple Product Badge

Thanks for your help!