help on shared libs/objs

Hi,

plz, explain me or say – where can i find docs
about shared libs/objects.

i raveled: what is different

  1. libS.a (variant “so”) / lib.a (variant “a”)
  2. lib*.so (variant “so”) / *.so (variant “dll”)

and my problem is that:
i link 2 libs lib*.so (variant “so”).
1st lib has no unresolved symbols.
2nd lib resolves symbols in 1st lib and
links to another with -llibname option.
i call dlopen() in main program.
then it calls dlclose() – and always
it causes Memory Fault during dlclose()!!!

What is my mistake?

Thanks!
vasilii