is it possible that the autofill function may be jumping in and adding extra text when you click ok based on an existing entry? try typing your correction and using tab to leave that field and see if the newly typed to/from stays as it is or changes to something else.
If autofill is completing the entry with misspellings or incorrect format, you may want to search your previous entries for that version of the to/from and correct it there.
Sending us screenshots based on the before, during and after editing the to/from field might help us figure out what is happening there. You can send those screenshots to
support@splasm.com with a quick note about your issue.