To unlock Idea NetSetter 3g Huawei E1550 this is what you have to do 
Find the flash code from 
http://a-zgsm.com/huawei.php
You would need the IMEI number. 


Now downloda the firmware update 
Rapidshare Link. 


Now Update the firmware 
1. Insert the modem to PC
2. Wait til Windows to recognize the device
3. extract & run the downloaded exe .huawei_firmware_E1550_StarHub_Update_11.608.13.02.00.B418.zip
 
Now insert what ever card you want and it will work. 


Even if the device is locked after 10 tries this will work. if you need help send me a mail . my device 
was locked and I got ti fixed. now I use an airtel sim to connect to internet.