an option in a product give '; on front end

-- url of the page with the problem -- : 2015.borduurstudio-deventer.nl/gastendoe...uct/1-gastendoek-wit
-- HikaShop version -- : 2.3.5
-- Joomla version -- : 3.3
-- PHP version -- : 5.0
-- Browser(s) name and version -- : Chrome + FF

Hello,

When i add an option to a product it gives on the front end at the bottom: ';
- Removing the option --> it disappears
- Looking at the product which is added as option --> it is not there

It occures with the 3 options i have right now. (2 with underlaying charectirestics, 1 just a normal article without anything special)

With firebug i see it happen, but i cannot figure out where it is or how to prevent it.

<form enctype="multipart/form-data" name="hikashop_product_form" method="post" action="/gastendoekjes/product/updatecart">
<input type="hidden" value="1" name="hikashop_price_product">
<input id="hikashop_price_product_1" type="hidden" value="7.5000035">
<input id="hikashop_price_product_with_options_1" type="hidden" value="7.5020121">
';
<div id="hikashop_submodules" class="hikashop_submodules" style="clear:both"> </div>
<div id="hikashop_external_comments" class="hikashop_external_comments" style="clear:both"> </div>

Thank you!
The tip works fine.