Well, just got back from Mexico and here are my findings:
The Obi110 speed dial feature did not interfere when dialing local numbers.
The bad part was that the local Telmex DSL line was too slow for any efficient ATA operation,
the receiving end was getting choppy audio but i could hear them fine. I did a speed test and I got these results. Ping 88 ms, Download 0.87 Mbps, Upload .08 Mbps
from these numbers i can see that the upload speed was too slow therefore the choppy voice.
I had no choice but to remove the Obi110 and install a HP thin client along with a magicjack attached to it, I then installed teamviewer 6 and I'm monitoring their PC/ service remotely.
I'll have to see in the future if they want to upgrade their DSL package so I can install the Obi110 next time I go down there.