Здравствуйте, Mutabor, Вы писали:

M>Описание проблемы:

M>в Tools.dll экспортируются два класса

M>class AFX_EXT_CLASS CResizeDlg : public CDialog
M>class AFX_EXT_CLASS CMyDlg : public CResizeDlg

default AFX_EXT_DATA and AFX_EXT_DATADEF macros for using or
creating MFC extension DLLs, depending on _AFX_EXT_IMPL
AFX_EXT_CLASS can be used to import or export entire classes
in an extension DLL without the hassle of creating a .DEF file
with decorated names.

какие preprocessor definitions у библиотек tool.dll и my.dll