I had the same problem. I solved it by using a very inexpensive wireless trigger that I got from Ebay. Not only did it keep my Olympus E510 from frying, it freed me from having any cords attached to my camera. They are called “Remote Radio Wireless Trigger Control Flash 4 Channel”, and cost $25.88. What a liberating feeling. You plug in the receiver to one of your units and the little sender to your hot shoe mount on your camera. Your other units will fire off by way of the built in slaves. You can get them from this store on Ebay.
http://stores.ebay.com/OEC-Camera-Accessories I have two, and keep one as a back up. You can get them for 30 bucks. Much cheaper and more useful then a safe sync and cord attached to your camera. Last, I have been using them for a year without any problems.