No probs but...
Basically there is no problem with traveling during Ramadan. Hungry people tend to be less enthousiastic, and smokers can be itchy.
Last year I was in Iran during Ramadan, and e.g. the theehouses in Esfahan where closed (the one under the bridge was open at night, bur really cold). On the positive side, we crossed the Iran/Turkey border the after the Ramadan ended. There where maybe three other persons crossing that day, which made for a very easy crossing, and what an amazing sight was Tabris in the morning with the streets full of praying people ... .
I've ended up three or four times in a muslim country during Ramadan, which is enought to find out I prefer traveling outside Ramadan.