R help - May 2004 - ld warning when installing packages with dll/so

Hi All,
When installing a package using C/Fortran routines I get a large of the
following ld warnings:


ld: warning multiple definitions of symbol _adler32
/Library/Frameworks/R.framework/R(adler32.o) definition of _adler32
/usr/lib/libz.1.dylib(adler32.o) definition of _adler32
ld: warning multiple definitions of symbol _BC
/Library/Frameworks/R.framework/Resources/bin/Frameworks/libreadline.4.3.dyl
ib(terminal.so) definition of _BC
/usr/lib/libncurses.5.dylib(lib_termcap.o) definition of _BC

My platform is:
platform powerpc-apple-darwin6.8
arch     powerpc   
os       darwin6.8 
system   powerpc, darwin6.8
status             
major    1         
minor    9.0       
year     2004      
month    04        
day      12        
language R  

The package seems to work fine, but I am surprised to get these warnings
because I did not them when installing under R 1.8
What is the reason of these warnings and how can I prevent them?

best, ingmar