You know what actually is weird? There are 9 M capitals that are six letters long and are alternating vowels and consonants - Monaco, Malabo, Maputo, Maseru, Moroni, Manila, Muscat, Monaco and Majuro.
I don't know if that's been discussed elsewhere on JetPunk, but is there any wiggle room for Muscat? I've seen it spelled Mascat quite a few times before...
It took me the longest time to get Moscow! There was one capital left that was in Europe, and I kept going all through all the European countries and their capitals, but forgot about Russia! But still got it in the end..