Currency Issues

Hi – tried posting this in the shopperpress forum but no answer and i see this section seems to be where most discussions take place so here goes. On my site when an order is placed it appears as GBP £’s all the way until it goes over to paypal at which point it changed to USD $’s – i’ve triple checked all of my settings on my site and everything is set to GBP yet as soon as it goes over to paypal it shows as $’s – very frustrating and site useless unless i can get a fix to this can anyone help?