My granddaughter has a Samsung Galaxy SII (ST)......she's had it since Sept. '12.....2 days ago she began having text problems...she can RECEIVE texts OK...but cannot SEND them....she keeps getting a "Message Failed" after hitting "SEND".... She has no trouble sending and receiving texts from Tango... I've had her do the "soft" reset (power down, remove/replace battery, power up) to no avail.....I don't want to have to do a factory reset unless it's absolutely necessary!! If it's a possible issue with APN settings...what should she/I be looking for? ANY HELP is appreciated! TIA!