joinsysdef wasn't properly translating the namespace prefix for "replace".
EXPORTS
?NewLC@CInvMessenger@@SAPAV1@AAVCConsoleBase@@ABVTDesC16@@@Z @ 1 NONAME ; class CInvMessenger * CInvMessenger::NewLC(class CConsoleBase &, class TDesC16 const &)
?ShowMessage@CInvMessenger@@QAEXXZ @ 2 NONAME ; void CInvMessenger::ShowMessage(void)