Hi Richard,
This is not a bug.
In Tools–>preferences–>others, there is a option called “smart keyword handling” if you enable that option even if you enter a string `default`, it will take default value of that column.
Uncheck that option and then try your case, it will work.
And also please refer this:
http://www.webyog.com/faq/8_99_en.html?highlight=smart%20keyword
Regards,
Khushboo