Spell-check works in the "Answer Box". Why not in the "What's your source" box?

Because the assumption is the source box will include a link to a site where you found your source, and that's going to drive spell checker nuts. lol

You have a couple other choices:

1. Get an off-site spell checker working too. (Mozilla Firefox has one, and Gingerly has one, although Gingerly only works right about half the time.)

2. Add what you would have added in your resource box to the bottom of your post. You can then choose to copy and paste it into the resource box, after the spellchecker works, or leave it where it is, and let the asker assume that's your source info.

They are probably expecting you to copy and paste a URL in there, that would always show up as spelled wrongly.

I don't use the yahoo spell check anyway because it doesn't recognise british spelling. My browser (chrome) spell checks for me, and it's set to british spelling. The browser spell-checks both the answer and the source box.