I think I didn't get it; apparently you are having a problem initializing the serial stuff.

As far as I know the init routine should be like this:

mov SCON, #050h
orl PCON, #080h ;double baudrate
mov TMOD, #020h
mov TH1 , #0F7h ; 2400x2 bd @ 16 MHz clock
setb TR1
setb ES
clr RI

which seems to be the same as what you have. Did you think about settings EA ? It seems you are disabling interrupts before setting the port ...