just checked this with MinGW GCC4.2.1, works ok, with the side effect that the the file is found twice !!!
Once in : c:\MinGW\lib\gcc\mingw32\4.2.1-dw2\include\c++\iostream
and once in C:\MinGW\lib\gcc\mingw32\4.2.1-dw2\include\c++\iostream
note the difference : c <---> C:
This is something we didn't have with MinGW GCC 3.4.5, or it should be a very recent regression; Can anyone check this with the latest svn on MinGW3.4.5 ? The earliest I can get hold of a MinGW GCC 3.4.5 system is on monday.