shows 4gb in properties, add 2 gb and its full, now check prop. and it now says capacity 2gb. have tried same file on sandisk 4 gb no prob, shows 2 gb left. Bought two of these by mistake and both same, would also question the class 4. cant really test but can say it takes twice as long to load file on this than it does the sandisk...mmmm. No doubt will be able to return as play are ok with returns but seems theve been had on these..dodgy batch?