Function Identifier Not Found

Hi,
I was trying to compile some code and I am getting a "Function
identifier not found" error. I can't figure out why since the
function that it claims is not identified is very clearly laid out.
Here is the declaration in my h file:

#pragma once
#include "afxwin.h"
class CGUIDlg : public CDialog
{
// Construction
....
// Implementation
protected:
...
public:
BOOL processEventMsg(time_t TimeSec, UCHAR chan, int strtID, UCHAR
*buf, int siz);
....
....
};

My function is written in the code as:

BOOL CGUIDlg::processEventMsg(time_t TimeSec, UCHAR chan, int strtID,
UCHAR *buf, int siz)
{
....
}

And it is called in another function as:

void getAllRs232( int lr )
{
....
processEventMsg(TimeSec, (UCHAR)(lr+8),elmThree*32, adrs, length-1); //
These variables have been declared and used
....
}

However upon compilation the error states that processEventMsg
identifier is not found. I've tried moving around the function to
different area of the code but it gives the same error.
Does anyone have any ideas about what could cause this?
Thanks very much in advance for any help!