Oh wait, wait. You said the formatting dies.
Does your CSS list styles in the order they are used? (It shouldn't, for other reasons, but never mind that now.) If so, the problem may not be in your HTML at all. It may be in your CSS, most likely exactly what you said in your first post: "failed to close a tag". If the CSS contains an error such as an unclosed bracket, the rest of the CSS will be ignored but everything before the error will be read normally.