In Firefox, why is my Oncourse CL window only half its normal size?

Using Firefox, if your Oncourse CL window appears at only half its normal size, check to see if you are using the browser's Adblock extension. This behavior has been found with the most recent version of Adblock, version 5d2 (build 39). To change the behavior of Firefox:

1. In Firefox, from the Tools menu, select Extensions.
   
   
2. To open the options for Adblock, double-click Adblock in the extensions list.
   
   
3. You should see a small box with the option to hide ads or remove ads. If the option to remove ads is highlighted, change it to highlight the option to hide ads.
   
   
4. Click Done, and then close the extensions window.
   
   
5. Refresh your browser, and it should redraw your Oncourse CL window at the correct size.