OS Error: The OS storage system (RAM, CF, SD, or IPSM) is not responding.

Hi

I've got a CE 3.5 database file that I can open in Visual Studio but whenever I try to access it from code I get a SqlCeException with the following message.

OS Error: The OS storage system (RAM, CF, SD, or IPSM) is not responding. Retry the operation.

I'm just running on a standard laptop with Windows 8 installed.

Any ideas what might be causing this?

Thanks

Ben