I am having a problem killing a timer I have set

I set the timer with:
Code:
m_TimerID = SetTimer(m_hWnd,1,5000,(TIMERPROC)TimerProc);
And I have tried both of the following to kill the timer
Code:
BOOL ret;

ret = KillTimer(m_hWnd,1);
ret = KillTimer(m_hWnd,m_TimerID);
Neither one seems to kill the timer, and the both return false. Any ideas on what I am doing wrong or how to kill the timer?

Thanks