Has anyone had any problems with the new (30mb/s) 4gb Extreme 3 compact flash memory cards, especially with trying to upload raw files from the camera (A200) to pc, either direct using the usb or card reader ?.

I'm having problems trying to import raw files (first time i've tried), the card was bought from play.com and to my knowledge they have'nt got a rep for selling fakes etc (I've never had problems in the past). All i get when trying to open the images after transfer is; this file may be unsupported or damaged & cannot open ....... .arw this file may be corrupted, any ideas please?.

I use Adobe lightroom/elements 4 & Sony image convertor.