Assuming 8 databits, 1 stopbit, no parity, using timer 2 for baudrate generation:

mov SCON,#050h
mov RCAP2L,#0DCh
mov RCAP2H,#0FFh
mov T2CON,#034h
setb ES
clr RI
setb EA

However, I still don't have a clue on the application nor did you post any code, so it's rather difficult to say what is actually going wrong here...