Ok here is a thought: I just read a little bit about Wordpress Mobile Kit, and it seems to deal with the mobile issue by switching to a different theme
A standard mobile theme, crafted by ribot, a top UK mobile design team.
A set of advanced themes for Nokia and WebKit devices, designed by Forum Nokia. These also look beautiful on Android, iPhone and Palm devices.
So, if these themes are being displayed to mobile users, they are probably NOT optimized for Woocommerce, and were not developed with that consideration at all.