I use revtex for my paper, and the sections are numbered as I. II. (roman), but when I use \numberwithin{equation}{section}, I get sth like (I.1), but I'd like it to be like (1.1), I looked around but didn't find anything to change it...
So if anybody can help, I'd appreciate it :)

revtex4class sections are numbered with Roman numerals; I don't think it's a good idea using two different representations for the same number. – egreg Jan 20 at 22:59