I've taken a look at the stylesheet page as described below:
As I stated, theme names can only be changed on the stylesheet. To see your stylesheet and edit it, go to Appearance > Editor. The stylesheet will open in the editor window by default.
in the stylesheet theme name and description, I see "abc".
In the dropdown in the upper right corner I see only the three options: abc, 2010 and 2011. There is no "BLANK_theme".
What am I missing? or (still) looking in the wrong spot?