I think I have a similar problem. When I send three 1s for example, I get two 1s and then another symbol different from the one I send. I am checking this on an LCD display that works. I am using HyperTerminal on my PC. I used a MAX232 that worked perfectly and an AT89C52 as microcontroller. Here's my code:

ORG 0
JMP principal
ORG 23H
JMP Rx

principal:
MOV SP, #070H

MOV TMOD, #020H;
MOV TH1, #0FAH; 4800 baud/s @11.059Mhz

MOV SCON, #050H;

MOV IE, #090H

SETB TR1; arranca T1

JMP $

Rx: ;--------------------------------- RECEPCIÓN
PUSH ACC
PUSH PSW
JB TI, salirRx
CLR RI
CALL printonLCD
salirRx:
CLR TI
POP PSW
POP ACC
RETI

Does any of you know what the source of the error might be? I'm sending 4800 bits/s, 8 data bits, no parity, 1 stop bit, and no flow control on the HyperTerminal.

Thanks!

Eduardo Hurtado