By the way, I believe that db2epub did not have this problem because its default output type was html. (imaginaryplanet.net)
Namely, when you open file in Sonic, it is instantly sent to our servers and converted instead of just being placed within the list queue and having to select the conversion output type (as is the case with Able2Extract). (lawsitesblog.com)
For the Default output type, we'll select DVD Folder. (howtogeek.com)