Update: I filed a support request earlier in relation to this current store window problem and have just received this reply from auctiva:
I apologize for the inconvenience you are facing. Currently, our site is experiencing intermittent but extremely slow periods as a result of which the store window is not displaying on the listings as well. This issue has already been reported to our engineers and will get resolved soon. For the time being, if the site is too slow to use effectively, please continue to check back with us as we are working diligently on a solution. You can even notice the same alert message displaying on your Auctiva account.
We apologize for the inconvenience.