Nasty Linker Error

Ok, everything compiles but when I go to use I get this linker error

------ Build started: Project: MLVDialogs, Configuration: Debug Win32 ------

Compiling...
MLVDlg.cpp
Linking...
Creating library Debug/MLVDialogs.lib and object Debug/MLVDialogs.exp
MLVDlg.obj : error LNK2019: unresolved external symbol "public: __thiscall ClFIFO::ClFIFO(void)" (??0?$ClFIFO@USuProtoMsg@@@@QAE@XZ) referenced in function "public: __thiscall ClMLVDlg::ClMLVDlg(class ClMLVDlg * &,class CWnd *)" (??0ClMLVDlg@@QAE@AAPAV0@PAVCWnd@@@Z)
MLVDlg.obj : error LNK2019: unresolved external symbol "public: __thiscall ClFIFO::~ClFIFO(void)" (??1?$ClFIFO@USuProtoMsg@@@@QAE@XZ) referenced in function "public: virtual __thiscall ClMLVDlg::~ClMLVDlg(void)" (??1ClMLVDlg@@UAE@XZ)
Debug/MLVDialogs.dll : fatal error LNK1120: 2 unresolved externals

Build log was saved at "file://h:\Sandbox\Elsys\Products\Common_Software\CSCIs\MLVDialogs\Software\Debug\BuildLog.htm"
MLVDialogs - 3 error(s), 0 warning(s)


---------------------- Done ----------------------

Build: 0 succeeded, 1 failed, 0 skipped