I am unable to recreate the problems encountered with the input filter. Will those experiencing problems please send me a Personal Message telling something I can find the thread by (your email, your secret URL, your thread title or message body)? Thanks. To prove I do indeed own it I have posted a message at:
http://sudo2.com/labs/Threadify/phpfreaks.html
Stating that I do indeed take responsibilty for this message and that I am who I say I am.
I have it set to allow "b", "i", "u", "br", "p", "a", and "img", so those ought to come through. I completely remove any other Javascript or other element. Bold, underline, italic, line breaks, paragraphs, links, and images are all perfectly appropriate in the context of a private forum thread, I think.
Please let me know if something is leaking through.