Non Disclosure Agreement and GPL

[Yves Autran]

I develop a software where I do have a NDA part, how can I handle this?

I have to link the code against :
glibc (LGPL)
libusb (LGPL)
libnova (LGPL)

if I refer to 
http://lists.gpl-violations.org/pipermail/tech/2007-November.txt.gz , I 
am allowed to hide the source code for the NDA piece of the code and 
publish the sources not relating to the NDA.

What should I tell the community ?
Can I still use the GPL licensing?
How should I behave with the LGPL projects owners/maintainers


Thanks a lot for your help in this case.

Yves Autran