Could we see the line it reported the error in?

Possibilities:

- You misspelled a style, class, or id at some point, so the stylesheet name doesn't match the name in the webpage code..

- You used a word for an IE built-in nonstandard style in another context.

- If you are using a strict doctype, you used a style attribute alone (e.g. 'checked') where it needs a value (e.g. 'checked=checked'). Lone attributes are not allowed in strict doctypes.

- You used " in a context where it needs to be " instead, causing the opening and closing of quotes to be out of sync.

- You put < in a style or a script.