I'm having a similar issue with 'custom' objects. First is trees - I have four different variations I'm alternating trying to figure out why it won't. The only trees that show up in my map are fir trees and oak trees but I have red oaks and cherry blossom trees in it. Exporting does not fix the problem.
Then I have an issue with crystals-with-no-glow not showing up but the crystals-with-glow will show up which is kind of amusing.
And yeah it all works perfectly in mapmaker and vanishes when I test it out on a character. I have also had a friend test it out and they don't see the items either so its again not something to be fixed by exporting...
It's so much easier to fix a problem when you actually know what the problem is. x.x lmao
Edit: Oh! Also the birch trees I downloaded from Wombat the other day won't work...pretty much the same as the cherry tree thing....Maybe there's a coding difference? *hunts*