Visual C++ General
First my usual comment - Visual C++ 6.0 is no longer supported.
I strongly suspect that the problem you are running into is that if gdiplus.lib comes from the latest version of the PSDK then it was built with a much newer version of Visual C++. This newer compiler produces new forms of debug information that is not understood by Visual C++ 6.0 - hence the message about "corrupt" debug information.
You need to either revert back to a (much ) older version of the PSDK or you need to update to a much more recent version of Visual C++.
It is very well known that the latest Windows SDK is not compatible with VC 6. The Windows SDK was previously called the Platform SDK. There is a Server 2003 version that is documented as the last version of the Platform SDK that is compatible with VC 6. If you go to the SDK downloads in the MSDN you should be able to find the relevant version.
I consider it quite strange that the latest version of the SDK is incompatible with versions of the VC compiler. The SDK is used by (compatible with) many other compilers; I think most other compilers. It seems really strange to me that the SDK is incompatible with any version of VC.