Curl Junkie's Site Having Issues

I've been trying to place an order since last night, but have been getting this message everytime I click the "proceed to checkout" button:

Invalid input. Please press your browser's back button and re-attempt your submission.
Please double-check that the characters you entered are normal A-Z or 0-9 alphanumeric letters or numbers. If you are using any special symbols in your submission, please remove them, and then re-submit your request.

Example of special characters would be the following: !@#$%^&;*-(),+={}?:"

If you continue to experience problems, please contact customer service with the following information:
Time of error: 11/30/2009 12:30:04 PM CST
Field Name: shipcompanyname
Web Page: /one-page-checkout.asp

Has anyone else experienced this problem?