Weird UART data rates

on LPC:

45.45 baud: 
U1DLM=255
U1DLL=45
	    (U1DL=65325)
MULVAL=1
DIVADDVAL=15

110 baud: 
U1DLM=104
U1DLL=40
	    (U1DL=26664)
MULVAL=1
DIVADDVAL=15