Howdy,
Ok lets say your specific addon your making is in a folder named "myaddon"
You have to have your textures in your buldozer directory to make them work properly, so make sure that folder is in your buldozer folder. Example:
c:\Oxygen\myaddon = WRONG
c:\Buldozer\myaddon = RIGHT
Also make sure its even 256^ or 512^. And paa, or pac.