Weird Table creation Issue with IE 8

See the uploaded screencast: http://screencast.com/t/782LEl01sAD

Steps to Reproduce

1. Create a page
2. Type in the following and press Enter:

   ||test||
   

3. A table will be created. After that, exit from the cell by pressing the down arrow button on your keyboard once
4. Then repeat by typing the following again and press Enter:

   ||test||
   

5. Notice that the table is not generated again this time.

The table will only be generated in odd intervals. No tables will be generated, however, in even intervals.

This is reproducible only on IE8 (IE9, Chrome works fine). Firefox experiences this issue intermittently.