I can import a level (any level) from FPSC to DBP with no issues as well. I currently use FPSC v1.17. One thing I did (as s4real mentioned) was have the following in my DBP code:
set dir "Files"
The above tells my code to set the root as "Files" so it knows where to locate what is required. The folder structure I have where my DBP app runs has the following subfolders:
Files\entitybank --> contains my static entities
Files\levelbank --> contains my level
Files\segments --> contains any segment textures not in the texturebank folder
Files\skybank --> contains the skybox I want to use
Files\texturebank --> contains the textures of all segments; if not in the path, then all segments are white.
Here are a couple of screens I have to show levels done in FPSC brought into DBP. I wrote my app to use the ZIP file created by FPSC that contains the level and required files so all I need to do is create the level in FPSC, then move the ZIP to my app. As you can see, it will work with any version (even v1), but will require some tweaking on the DBP side to ensure it knows what to look for.

There's no problem that can't be solved without applying a little scripting.