Hi Community,
Thanks for helping to bring this to our attention. I believe most or all of you are being affected by known issue that is causing the multi variation interface to hang up and display a "Processing" message when used through Internet Explorer 7.0 and our engineering team is currently looking into getting that issue resolved as soon as possible.
Since the issue in specific to Internet Explorer 7.0, you should be able to work around the issue for the time being by upgrading to Internet Explorer 8.0 or by using the Firefox browser. The Firefox browser can be downloaded free of charge from http://www.mozilla.com
Also, when you change your plan from one paid plan to another during a given month, it is expected behavior for the new plan to take effect on the first of the next month.
In the event you would like to upgrade your plan for the current month, please contact our customer support team using the "File a Support Request" link on our help page and we can help you out with that.
-Mike