Having problems copying 30 gig of data to a 32gig sd card.

Its a brand new samsung card off egay and its been formatted correctly.

I can copy a few files over but regularly every gig or so it fucks up and claims it is unable to read or move the files im copying as they are corrupt or unreadable.

the originals are fine.

I have to go to the scandisk utility within properties and it finds and fixs errors deleting some of the stuff i copied in the process.

Is it likely a duff card???