Если процедуру void PortDOWN(unsigned short port)вызвать из программы, то все работает.При попытке вызвать из DLL пишет (win98, помогите, plz, очень надо)

file: i386\chkesp.c
line: 42

The value of ESP was not properly saved across a function call. This is usually a result of calling a function
declared with one calling convertion with a function pointer declared with a different calling convention.

-= Программа =-

typedef void (CALLBACK* PORTUP)(unsigned short);
PORTUP PortUP;

skip

void COpenDtestDlg::OnOpenButton(unsigned short port)
{
PortDOWN=(PORTDOWN)GetProcAddress(hDLL,"PortDOWN");
PortDOWN(port);
}

-= DLL =-

#include <Windows.h>
#include <conio.h>

void PortDOWN(unsigned short);

BOOL WINAPI DllMain( HANDLE hModule,
DWORD dwReason,
LPVOID lpReserved
)
{
switch(dwReason)
{
case DLL_PROCESS_ATTACH:
break;
case DLL_PROCESS_DETACH:
break;
}
return TRUE;
}

void PortDOWN(unsigned short port)
{
int databyte=0x00; // 0xFF
int reflex=_outp(port, databyte); //port 0x0378 или 0x378
}