Calculate button does not use changed code

Checkio Javascript

If "Calculate" button is pressed it will use the correct code as displayed in the code editor window the first time it is pressed (for example "return 1234;" will return "1234").

If the code is changed (for example, "return 5678;") after the "Calculate" button is pressed subsequently, it will not use the current code (as shown in the code editor window) and will still run the old code (ie return "1234"). Pressing the "Check" button DOES use the correct code. Pressing the "Save" button then "Calculate" does not save/run the correct code either.

I have to refresh the browser window to change and run the code (via Calculate) each time there is a change.

Browser: Firefox. By default, I have cookies turned off and NoScript running. I have enabled cookies for checkio.org (http and https) and all scripts on the page are set to Allow.

I have also tested in Chrome with default settings (cookies and scripts allowed) and same issue.

Any ideas?

Thanks!