I'll be glad to help.
1. Which Windows operating system are you using?
2. Does this problem happen when typing text on the label, or typing text in the Text Editor on the left side?
3. If you open a new blank AudioLabel project, does this error still occur?
4. If this problem only occurs on one AudioLabel project, could you please email us the project file (ending in .aud) so we can test it here?