I finally managed to fix the update problem on my Echofon application. It seems that the latest update on Echofon is not a stable one (in my case). Even though the Changelog stated that it fixed some problems, but it also caused me more annoying problem as i can't receive any update at all
The one mentioned on Mozilla's Addon site is still at version 2.1, not 2.1.1 as mentioned on Echofon's website (the one they offered when you install it from their website).
Anyways, it's back to it's sane mode and i could start tweeting again from my favorite browser (Firefox)