Missing characters/not expanding correctly

I just started having this problem where I'm missing characters as I type, almost like it would if a key is stuck, but it's not the same character key every time. I thought it might be my keyboard, so I purchased a new keyboard, and I'm still having the issue. It only happens when I have InstanText up. Additionally, occasionally the expanded version of the word does not come up correctly, even if it's correct in the glossary. I even went as far as resinstalling InstanText with no improvement. Please help! My speed and accuracy are going way down as a result because I depend so heavily on my InstanText.