Just caught the Merpati flight from DPS to Dili today, and was able to check in a 29KG bag with no extra charge. I told them that it was sports equipment (dive gear), and they still suggested that I should pay for the extra 9KG so I pulled out the "but all of the other airlines give you 30KG for sports equipment???" End result - no fees. I also carried on my LowePro Trekker 600 AW, and a smaller North Face backpack for my laptop. No questions, no weighing. If you are one of the first ones to board the plane you'll have room to stow them overhead. When everything fills up they'll make people check a carry-on that won't fit under the seat.
Did you buy your ticket in advance or did you buy when you got there?
I'm going to Dili on Sept 1 but have had problems purchasing a tkt in advance.
So far I'm rolling the dice hoping the plane isn't full when I get there