me and john dos passos vote for the hyphen in dub-dub but not in hubbub. we think the hyphen serves as a necessary syntaxal pause in dub-pause-dub. otherwise hyphenate only for the mental image of a thing that has been altered by joining. but in general join words together like germans. it'll look poetic and make your sentences read smoothly. i am writing in the lower case not because of any ee cummings literary air but because mister petee is sitting on the shift key and won't move. mister petee is a cat.