[openasocket]

It would seem not! I found a copy of the paper: http://www.cs.cornell.edu/courses/cs682/2006sp/handouts/benn... and it doesn't seem to specify any conditions. Apparently prior work has constructed specific oracles X such that P^X != NP^X. I think the paper is "Relativization of the P =?NP question" but I couldn't find a copy. Though I did find this http://www.cs.umd.edu/~jkatz/complexity/f05/relativization.p... which might help.

[JadeNB]

Thanks for that reference! I am glad that, even if my intuition led me astray, at least I had the foresight to append the weasel "… right?" to the end of my false claim. :-)