I get txt from those I'm following on my mobile, but when I post from mobile, it doesn't show up in my updates

hey. i had this problem too and figured out a way around it. try this to see if it works: text 'quit' to the twitter number. then type in your mobile number again in the 'add device' function on twitter (only this time recheck the country code before entering it, i had the incorrect country code before), then follow the instructions from there. try that; i don't know if it will work, but it did for me...