The spell check is not registering spaces. if I write ‘but I wasn’t’ it will underline but, I, and the w is wasn’t in red and give me the suggestion of Burtie.
This happens in mine as well. A lot of the text in the tutorial is underlined in red. Not sure if this is remotely helpful, but here’s a link to a screenshot: i55.tinypic.com/238l8k.jpg
This is exactly what I am talking about. I never thought to take a screenshot of it. Thank you for thinking for me. 
No problem! 
I’m used to being prompted to provide screenshots for issues. It helps that sometimes I’m terrible at explaining problems.
Happens in mine, too - a lot of things underlined when there is a space inbetween.
Also, I noticed, spellcheck automatically happens in British English. Any chance of changing it to American English 
Thanks everyone. I’ve been able to duplicate this as well and will add to bug fix list. You can disable spelling features in the options dialogs last tab. Thanks again.
I’m having similar problems. I typed “beach” and it’s telling me the “ac” in “beach” is wrong and wants to replace it with “AC”.
I think spell check has difficulty in recognizing the apostrophe that you automatically type: For example it corrected “couldn’t” with “couldn’t” but the apostrophe was slightly different. I’m not sure why it would have a different apostrophe, but it seems buggy to me!
when I typed in doesn’t the “doesn” part was underlined as a mistake. but the t and the apostrophe was not. also i have experienced the misplaced underlining when i misspelled concerning. it underlined “serning t” the t being a part of my next word.