[cozzyd]

Thanks. To save others the trouble, a (apparently accessible to all?) link to that article is at http://projecteuclid.org/download/pdf_1/euclid.ss/1009213286

It looks like Clopper-Pearson is the only method guaranteed to not underestimate the size of the confidence interval (which makes sense, given its derivation), but it almost always overestimate its (unless your confidence interval exactly matches the discrete p-values allowed by the binomial distribution).