Hi,
The popup you are talking about is a bootstrap popup.
Are you really really totaly and definitly sure that you really have the "mootools" mode for your HikaShop popups ?
This popup is added by the HikaShop cart module in order to let the customer print is cart.
You can deactivate this feature or check that you use the mootools popups.
The "showcart" view use the HikaShop popup helper so it use the popup system configured in your HikaShop configuration.
Regards,
Jerome - Obsidev.com
HikaMarket & HikaSerial developer / HikaShop core dev team.
Also helping the HikaShop support team when having some time or couldn't sleep.
By the way, do not send me private message, use the "contact us" form instead.