I suggest improvements to forums as follows:
1. Put a message on the screen where you write your post explaining the <nospellcheck> tag, or put a phpBB'esque nospellcheck button at on that page along with a bold, underline, and italic button.
2. Display which forum the post is being made in with larger font, or in a different more visable area.
3. Make the spelling check page display a bold message saying, "If you are using the <nospellcheck> tag in this post please disregard the misspelled words listing below and click the post button below."