100% with you: Durian pastries in Singapore are bland. Honestly, I haven't found pastry form of Durian that great, and I love, love, love durian since I was a kid (I'm Indonesian).

Keep in mind that there are over 200 varieties of Durian - some are even red inside, some sweet, some more pungent than others, different notes and textures. The best for me is Musang King variety in Malaysia, esp. when they get a slight alcohol after taste.