voltage problem....need help!!

Dear Sir,
I have 2 xbee modules as XB24-ACI-001 & want to communicate it by using at89c52controller.
my aim is that to use it as switch controller i.e when i press switch from base station led on remote station will on/off accordingly.I use at89c52 controller which work on 5v & xbee 3.3v, connection between controller & xbee is as
Rx of controller directly connected with Dout of xbee &
Tx of controller connected via voltage divider(R1=1.5k & R2=3.3k, Vin=5v ,Vout=Vin*R2/(R1+R2)=3.4v) with Din of xbee .
my question is that

  1. when i give supply to this module ,i get voltage at Tx & Din is 0.54v rather than 5v & 3.3v approx. resp.
    how can i correct this problem?
  2. when i give direct supply to xbee ,led on pin 15 (ASSO) is fast continuously glowing how can i reset it?
  3. How can i check my xbee module is working correctly or not?
    4)for coding purpose i refer Rob’s code in that he mention if(serial.available()>1) i dont understand this statement how i know that the data is in buffer?
    5)i use Keil instead of Ardiuno for programming.