CSS Menu Writer Not Working

I was trying to add a menu to a new web page. I created the contents and then moved on to edit the "theme". I changed the fonts, sizes, colors, and then when I was almost done, it just hung up and stopped working. I had to click cancel and start over. I did this twice and each time (at different points) it just hung up and stopped working again. Then I completely closed Dreamweaver and then reopened it. Now when I click on the script button and click "Edit Theme" the window for the editor starts to open and then quickly closes - I can't get into it at all. Then I came to the forum here to look for a solution. The first thing I did was to delete the .dat file (the first thing that I am always told to try whenever there is any kind of problem). That did not fix it. Then I realized there as a new version of design extender, so I followed the instructions, removed the old design extender, installed the new one, closed and reopened Dreamweaver (CS4) - still the exact same problem.