fatal error C1001 when using templates

[JimmyS]

I am getting this error ..
c:\Program Files\Microsoft Visual Studio .NET
2003\Vc7\include\stl_alloc.h(305) : fatal error C1001: INTERNAL COMPILER
ERROR (compiler file 'msc1.cpp', line 2701)
when including any files for templates .. #include <fstream> ,
#include <string>, #include <vector>, #include <list> etc...
The funny thing is that was not happening before, it really used to work
fine with templates. By removing the STL include files the error dieapperas.
Has anyone else encountered this problem ??
Could it be some application, or an update, that has been installed?
I even created an empty console project, it gave the same error when I
compiled it .... however when I removed the "#include <iostream>" line from
"stdafx.h" it compiled fine.
I am using Microsoft Dev Env 2003, ver. 7.1.3088
Microsoft .NET framework 1.1, ver. 1.1.4322 SP1.
Thanks ....