Cant access checkout with wp e commerce

so basically i am in the process of building this site that sells a virtual currnecy. the url is: http://www.onlinefutcoinstore.com

recently i was changing some settings in my wp e commerce plugin, and updating some of my products. I went to test out my shopping cart and make sure evrything worked correctly. All my products showed up correctly and evrything and i was able to add things the shopping cart. But then when i tried to proceed to ” checkout “, wordpress just froze and i would eventually get an error page saying ” this page is not available. interestingly enough, when i deactivate all the e commerce plugins, and go to my checkout page again, it works, obviously thers no shopping cart or anything but the page works. One other issue with this is, now whenever i turn on wp e commerce plugins, i cannot access my list of pages in my admin dashboard area.