Apple’s new MacBooks – specifically the 15in and 17in models – are freezing up under duress. That’s the message from Apple Support forums. Or rather the growing stack of messages complaining that the machines crumple when faced with big jobs like video encoding. Fingers are being pointed at the new AMD graphics, thanks to a home-grown fix that eliminates the problem by switching to integrated graphics at the cost of performance. We had no such problems when we tested the 2011 13in MacBook Pro recently. Here’s hoping the issue can be fixed permanently with a download rather than a refurb. Keep an eye on the forums here.