I had a couple of problems decoding alphanumeric sender addresses for received SMS's.  It was in gsm-encoding.c in char_bcd_number_get:

 - The Type of address value (0xd1) was not recognised (i.e. alphanumeric + ISDN)

 - The length passed to char_7bit_unpack was 1 byte too large

Here is my hack to fix it, but the 0xd1 needs to be added to the list of types I guess:

1104,1105c1104,1106
< char_7bit_unpack(0, length, length, number + 2, buffer);
< buffer[length] = 0;
---

> case 0xd1:
> char_7bit_unpack(0, length - 1, length, number + 2, buffer);
> buffer[length - 1] = 0;

I am using gnokii 0.6.28 but it seems to be there on git also.

I am reading the SIM using a card reader:

[global]
model = APDU
connection = libpcsclite
port=0


[logging]
debug = on
rlpdebug = off
#xdebug = on


The SIM is for the Spanish Orange network.  Telephone is a Sony Ericsson T250i.