g++ namespace std & BUG?

[Mark Wall]

Hello!  I was excited to successfully install gcc-3.0.1, but now I
have compiling problems with many lines of old code.  None of the STL
functions like "cout" work without explicitly declaring "using namespace
std;".  I can live with that.  PROBLEM: Other cstring functions do not 
work properly (e.g. "strcmp" do not return 0/1 when there is
match/nomatch).  Previous gcc versions compiled this correctly.
Unfortunately my searches for a  solution are futile.

Please help.

Mark Wall