I've had my MacBook since 2006 and, on the odd occasion, I've used the FireWire 400 port for connecting an HDD caddy or for networking between two Macs. I've always hot-swapped devices without a worry. I've always assumed that's what FireWire was designed to do.
However, recently I purchased an M-Audio ProFire 610 - it's a multi-channel digital audio interface - and plastered all over its documentation (and the website) are warnings that you MUST turn the device off before plugging or unplugging. I was quite surprised by this, and wondered if it had anything to do with the device being dodgy.
Apparently then, this is not an issue with M-Audio devices, but with ALL FW400 devices... Although it's the first I've ever heard about it, which I find a bit odd... If there really is such a fundamental flaw in FW400, why wouldn't I have heard people complaining on Mac forums about fried FireWire controller chips?
Is it dangerous in general, or do you think that perhaps M-Audio are trying to cover-up for shoddy manufacturing? Like I said I've never had any problems hot-plugging FW devices before and now I'm really paranoid, turning the computer off every time, which is really frustrating.
Not only that, but supposedly the issue is power arcing onto the data pin... But if you power down any Mac device (MacBooks included), they still deliver power to the FW device. So how safe does powering it down really make it anyway?