say you have an invisible field where the value contains an equal sign - this causes the value to be truncated improperly and prepended with a containing quote. some examples might be like in ASP pages where you have a viewstate which is base64 encoded and has a "=" buffer at the end.
if you have a tag:
the attribute/value pair is returned as:
this can be fixed by adding ",2" to the explode method on tidy_parser.php line 305 like so:
$parts = explode('=', $raw,2);