Matt,
Are you using a custom template for your Shopping Cart pages, or are you using a built in template?
It looks like the code for the registration links is not correct. When you view the shopping cart source, the New Customer link should look like:
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New Customer?
<a href="https://secure.shopsite.com/cgi-bin2/sc/registration.cgi?func=1&storeid=*1aa45145a0cfc26c0e8f6c8e179a57&fromid=order.cgi&sbid=SSMSB1184799205.6173&prevlocation=http://laurenannjewelry.com/124bct.html">
Click here to <b>Register</b></a>
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Rather then:
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New Customer? <script type="text/javascript">
document.write('<a href="javascript:__utmLinker(\'https://xterius.shoqhosting.com/~tsplines/cgi-bin/sc/registration.cgi?func=1&storeid=*14c77f794ae441461a987f44&fromid=order.cgi&sbid=SSMSB1185216318.3810&prevlocation=http://www.tsplines.com/store/\');">Click here to <b>Register</b></a>');</script>
<noscript>
<a href="https://xterius.shoqhosting.com/~tsplines/cgi-bin/sc/registration.cgi?func=1&storeid=*14c77f794ae441461a987f44&fromid=order.cgi&sbid=SSMSB1185216318.3810&prevlocation=http://www.tsplines.com/store/">Click here to <b>Register</b></a></noscript>
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I am not sure why it is not the correct coding, however if you are using a custom template, you can make changes in your custom template to fix this. If you are not using a custom template, you can go to Merchandising > Custom Templates > Shopping Cart Templates > Copy ShopSite Shopping Cart Template, and make a copy of the sc_default template.
You can then go to the URL listed below, and copy the script from that page. You can replace the [-- SC_Registration --] tag with this script. (or if you were not using this tag to begin with, and you were adding your own code to the template, you can try using this tag).
http://www.shopsite.com/help/8.3/en-US/ ... cript.html
You can then make sure that your custom template, is the one that is being used in the cart by going to Commerce Setup > Order System > Layout Info.
-Lauren
ShopSite, Inc.