[Tinyos-help] RSSI value interpretation

[RamKishore]

Hi all,
           I use mica2,tinyos 1.1.10.I receive the following RSSI values 
in Hex for Max and Min Transmitter power :

 00 4f(Tx power =5dBm)  and  01 31(Tx power=-20dBm)
When 2's complement is taken we have:-79 and -305
To these values,-45 should be added.So, we have -124 and -350 respectively.
These values are in complete conflict with the CC1000 manual,which says 
that the dynamic range of RSSI values are -105 and -50dBm.

Are there any interpretations?I am really confused with these 
calculations.please correct me..

Many regards,
Kishore