Actually titles of books, titles of songs, and title of movies cannot be copyrighted. That is why you see them having the same name. Of course many people will not use the same name because if you want to have a movie that is huge on it's own merit, you don't want it to be the same name as something else. But legally it is allowed. Having said that I am not sure how that applies to patterns and quilt names because those are more like company or product names. Generally speaking two companies can have the same or similar names so long as they are not in anywhere near the same business. So I guess if you are going on that you should be fine, however, I agree with someone else that if people were to search for your pattern name in Google the other quilt may come up, which would be confusing. Perhaps you can think of a derivative of the name to use for the pattern to make it more unique?
Rachel