Having read these posts, I find it amazing so many "armchair Pilots" that have a knowledge of International flying.
Dick Smith is strictly correct, BUT you are over flying their country and after some 30 years of International flying and Operations the safest bet is always go for the approvals.
For Indonesia, you just ring Dude up in Bali and he arranges everything for around $US200 plus expenses. And then he also arranges all the extras at local costs so in the end you save money.
Even if you are just transiting you are better off getting the approval for a landing overnight. You never can be certain around that part of the world with weather, volcanic activity or getting into a tech stop only to find the aircraft go "technical"