Potato chips ..or crisps: a reader asks

I've been asked by a reader if I can refer him to a decision which he vaguely recalls, which concerns either a national design right or a registered Community right (he thinks) in respect of the shape of what we Brits call "potato crisps" but which are sometimes referred to as "potato chips" (generally by people who call what Brits call potato chips "French fries"). It might be an infringement case, or possibly a cancellation -- but the two absolutely certain ingredients are "design" and "potato crisp".

Offhand I can't think of one, but I wonder if any reader can help jog a couple of jaded, faded memories. Please!