Here's what I did to unlock my NEW Smartbro Huawei E173 (u-3) modem:
1. Calculate the FLASH and UNLOCK code. Use the unlock code calculator. Download it from here
http://www.mediafire.com/?dcax8h3d11c59s1
You need the FLASH code when you update the firmware.
2. Download DASHBOARD UPDATE and FIRMWARE UPDATE here
http://dc-files.com/files/huawei/modems/E173/
3. Install the DASHBOARD update. (Huawei Generic Dashboard)
4. Install the FIRMWARE update.
5. Remove the dongle, insert a different network sim like Globe or Sun.
6. Wait for the dashboard and the unlock code PROMPT to open. Input the UNLOCK code.
7. Create a new connection profile:
GLOBE
APN: http.globe.com.ph
SUN
APN: minternet
SMARTBRO
APN: smartbro or internet
Access Number: *99#
100% working for me!
Just be careful with updating. DAPAT hindi ma-interrupt while updating is in progress. You need to have enough battery/electric power.