I had this running on a site with no issue and then just noticed that I got this message in the widget - "One or more parameters are invalid in request".
I deactivated and reactivated the plugin. I also deleted the widget and added it again. I just requested new API token and secret but still the same message.
Here is the website - http://www.pushkinsbakery.com/about-pushkins-bakery/.
Let me know if there is anything else I can try. I have it running on another site of mine for a different business work no issues.