Backports packages in red letters.

Several packages (if not all) in backports.org when we search them in http://packages.debian.org/ appear with the letters in red: backports(in red),is this a specific warning sign? Or just to remember that these packages do not have security updates treated as the packages in stable?Examples:gnash,

Difficulty setting up gcc packages.

I set up gcc,gcc-4.1 using apt,which installed the necessary packages (I think) and now running the configure script of opensource software(not in Debian) I have this message: configure: error: C compiler cannot create executables,see "config.log" for more details. I cannot find any file with tha