We have discovered a problem when using IE 8 that is solved for SmarterMail 12.2, but are unaware of any other problems. Regarding the green box, that's how the spell check works. When you're in spell check mode, a green box appears around your text, and misspelled items are underlined in red.
We'll check on the spell check before send option.
Do you have additional details on what browsers people are using when these errors occur?