Yes, as is evidenced by the number of posts in the Yahoo Answers subcategory about this very topic. There is a problem with the Submit button. Make sure you aren't hitting the button more than once. If it seems like your post isn't submitting properly, copy the text you typed, refresh the screen, and if it doesn't show up as posted, paste the text back in the question or answer box, and try again (usually a screen refresh will show it as posted).
Always check the YA subcategory first, if you're having issues with the site or want to know how a feature works. Chances are, someone (or many) have already asked the same question and received valid answers.