[flexcoders] Why are source path folders sometimes copied to the output folder

[boy_trike]

I have a main application (called lumber) and 4 other projects (modules).  Each 
of the 
additional modules has  the lumber folder added in the Flex Build Path / Source 
Path as 
"${DOCUMENTS}\lumber".  When I compile my programs, 3 of the 4 additional 
modules bin 
folders contain a folder called "[[source path] Lumber]"  (1 of them does 
not!).  I have no need 
for this in the output folder.  How do I stop this from being created?

Thanks
Bruce