Ive installed Antix M8 and its working well with a T-mobile usb dongle made by Huawei - Model E160.
I was messing around with some settings in umtsmon, when all of a sudden I lost contact with the world. I tried to reconnect but Umtsmon told me there was no carrier.
I looked at my dongle and the little light was flashing green. Usually if disconnected it flashes blue, when connected the bue light is on constantly. When transferring data the blue light gets brighter.
I tried unplugging the dongle then plugging it back in - no change, so I rebooted antix, still no change. I took the sim card out and put it in a phone, within a few seconds, it was connected, so I tried again with the dongle, it was still the same. by this time I was pulling my hair out.
I tried another sim card in the dongle, and there was a signal. I didnt try to connect because I would have to change settings. Still there was no signal with the t-mobile sim in the dongle.
My last resort was to try it in windows, still the dongle flashed green and didnt work.
I unplugged the dongle and uninstalled the software from windows, so when I plugged it back in it would go through the process of installing again.

After all that my problem was solved and my blue light was back.

I will leave this open for a couple of days, just in case anybody has a comment,
maybe there's an easier way........