Hi,
You should go in the menu System->Currencies and edit your currency. Please make sure that it's properly setup, like the default settings.
For the cart button, that's because your template displays the style of buttons with javascript and not pure CSS. You have several options:
deactivate the ajax refresh so that it does a full refresh of the page. You can edit the view and change the code for that.
change the template (or it's options maybe) so that it uses only CSS.
set the option "button style" to CSS in the Display tab of the configuration so that hikashop uses it's own style of buttons and not the one of your template