Why can't TouchPal use real spell-check?

I really like the TouchPal virtual keyboard, but its implementation of spell-check/auto-complete on the compact qwerty keyboard is really frustrating to me. Instead of looking at the whole word, it looks at the string you have typed. The moment you make a mistake that doesn't map to a word, it reverts to assuming you are using it in non-auto-complete mode, so that you get the nonsense word that is formed by the first of the two-letter pairs. In other words, it defaults to something that is wrong 100% of the time. I am probably missing something, perhaps it is a matter of computing overhead, but this implementation really mars an otherwise terrific product.