Spell check problem

I can't seem to figure out how to have my Z30 not change so to do on text messages. I know I can swipe up on the space bar or turn off spell check completely. Since I forget the swiping up about half the time it's the most annoying freaking thing I've ever seen. I only have issues with the word so, (just now it was going to change it again). There must be a way to eliminate it from spell check or override the default word that's suggested. Turning off spell check completely works but it's a bit drastic for 1 two letter word and putting it in my personal dictionary has no effect. I'm sick of idiotic sounding messages to my boss, I need a solution.

Posted via CB10

just backspace and correct it? I don't see many choices here. or set up a word substitution entry for so to do