heres the problem:
when you save your land in visitor as .WRP buldozer simply needs to see land!
How do you get land in Buldozer? open your island, press ctrl+f7, wait till buldozer opens, press ctrl+f8 to refresh, wait some time in visitor while in the upper left corner of buldozer some text flickers between con and busy, if thats ready you can see land
(still no land? just scroll a bit, maybe textures won't show up in that part)
if you see land just save it as wrp
tip: save your textures in your island, the island will get bigger (file-size i mean) but you can use much more textures!
about Tutisland.paa thats the pic which shows up if you click mission-editor in the main menu and when you choose your island to build the mission on. You just have to save the tutisland.paa in your island addon (in the pbo)
hope thats enough