[Plugin: eShop] Firefox 501 Error upon checkout

Hi,

Im using the elegant themes’ boutique theme and eshop. My site is: http://www.creative-motivations.com/cmblog and im using web hosting hub for my hosting site. Upon testing out my shopping cart, I’m getting an error page. It has happened 2x now. I get all the way to checkout on paypal, where u enter ur credit card info as a guest and when I click the link to return to the site, I can’t, I get this error page:

———————————————
Method Not Implemented

GET to /cmblog/ not supported.

Additionally, a 404 Not Found error was encountered while trying to use an ErrorDocument to handle the request.
———————————————

except the /cmblog/ had a longer address most likely… this is a copy of the page I get when I just type in my address http://www.creative-motivations.com/cmblog

this also happened when I didnt click the return link, but just opened another tab and typed my address and BAM, error, couldnt view my site… Im using firefox and its a 501 error. Upon doing some digging around Ive discovered that clearing my history solves the problem, and I am hearing that its a mod security issue associated with the eshop plug in. It happens even when I try it on someone else’s computer, thus it will happen to my customers as well. I cannot continue using eshop if this continues to happen. HELP!

How can this be fixed? Thanks so much.

http://ww.wp.xz.cn/extend/plugins/eshop/