It is quite a bit more apt to produce DMS, but pH has little to do with it. Typically, DMS is combated with a longer boil, as DMS is volatile and driven off in a boil. That is why you often hear about people boiling their lagers for 75-90 minutes or even more. Believe me, you often can smell the corn coming off those boils, too.
Also, chilling your wort is important to minimize further DMS formation once the wort is below DMS's boiling point.