note 14185 added to function.strip-tags.php

I'm having one small problem that I believe may be the fault of the strip_tags function. I'm displaying pages from a remote user account on my site and I'm running the pages through strip_tags to remove some things I don't want (font tags, that sort of thing). One of the pages has a form on it and I need the form to call a JavaScript form checker. Unfortunately, when I call onSubmit='return functionName();' it seems to be losing the parentheses. Does anyone know of a problem like this? Or is it the fault of something else? I would APPEAR that strip_tags is removing the parentheses from my form tag. http://www.php.net/manual/en/function.strip-tags.php