Recently, downloading symbols for microsoft shipped binaries using the Microsoft symbol server (http://msdl.microsoft.com/download/symbols) broke for Visual Studio 2003 users. Microsoft has disabled downloading symbols using older versions of symsrv.dll for compatibility reasons.
To resolve this, you need to update the symsrv.dll on your machine with a newer version. Symsrv.dll is a component that is updated periodically, and the latest version can be obtained from the debugging tools for windows package at http://www.microsoft.com/whdc/devtools/debugging/default.mspx.
Simply replace your Visual Studio symsrv.dll (located next to devenv.exe) with the one from the debugging tools package, and everything should start working fine.