Lpc2000

I have created a frequency generator using timer1.  I have had 
problems loading the match register on the fly.  Sometimes I start 
losing interrupts.  I have tried simply disabling the timer when I do 
a reload, but it doesn't seem to help.  What does work is something 
like this:

DWORD dwMatch;

dwMatch = ...;  // calculate new match value

if (dwMatch != T1MR0) {
    T1TCR = 2;       // disable/reset timer1
    T1MR0 = dwMatch; // reload the match register
}

T1TCR = 1;      // enable timer1

The key is the "reset" of timer1 before the reload.  Does anybody 
know why this is the case?  Is there a better way to accomplish this?

Thanks,

JT