For the last few months I've been using my D200 in the studio, and it's been quite happy plugged into a big old Bowens flash rig.
I decided to try it out with a portable Norman 200b setup, which worked fine for about an hour, and then the flashes stopped flashing. And so I pulled the sync lead out, and had a look at it, and then plugged it in again (a technique that I also employ in other instances of performance problem), which resulted in the flash firing wildly. So I stopped. And then searched on the internet, and discovered that plugging big old flashes into digital cameras is not such a great idea. I think I have killed the pc sync socket / circuit. I will get my man to check it out at some point.
Anyway, it turns out that what you need is a Wein Safe Sync device. This plugs into the hotshoe, and has both another hotshoe fitting and a pc fitting. The device apparently reduces the flash trigger voltage to 6v, which is safe for both Nikon and Canon. That is working fine now. I understand that Canons are more susceptible to damage, and people have managed to completely fry the main board in this way. What I thought was a little bit strange was that there didn't appear to be anything in big red writing in the Nikon manual about not plugging in flash equipment...
