Two issues, one minor, one MAJOR.
I discovered both of these while trying to post on the forum.
First: (minor)
When the message entered is longer than the height of the editor itself, the scroll bar appears on the right correctly. However, when you click ABC to spell check, the scroll bar and the text area are shifted down by the "Spell checking mode" box. This results in the inability to view the last two lines of text in the editor b/c of the shift.
Secondly: (major)
I was typing this message, and in attempt to recreate the problem. I typed a whole bunch of random text ("aasdf" and the like) and then clicked ABC. Obviously it found errors. I clicked the Cancel button on the "Spell checking mode" box. I then deleted the garbage text and started typing this message. I had very little text written when I clicked ABC again. I got an alert that said "No mistakes found." However, to my surprise, all of the text that I had typed was now gone, and replaced with the garbage text I had just erased.
I tried replicating this again and got the same error. I then tried replicating it with a typo in the new text and the spell check functioned normally.
I hope you can replicate this and get it resolved.
Let me know if you have questions.
Thanks and Happy New Year!
- Oleg Fridman