Seems that many, many folks have forgotten what a Yippie is, or that they ever heard the word before. This includes folks who you would think would know a lot about the group, like those older than me who were one step away from being Yippies themselves.
Found the same effect with the Weathermen too, though not as much.
These days people do recognize the alternative spelling of America as "Amerika" and might not really know what it means, but they are familiar with it. So the new title is Time Bomber: The Movement in Amerika, from the phrase used in the bomber's notes.
Will get back into Gimp and rework the cover sometime when I can get to it.