I have too also.
It sucks because the drivers side back bolt is directly under the header tube and against the firewall. I have one wrench that I heated up and bent at almost a 90 degree angle just to get to it. And thats after your practically laying in the engine compartment to get to it. I've lost count how many times I've had to change header gaskets.

One thing I've used is the washers by mr. gasket. There not locking washers just plain black thick ones. They work for me. They used to come loose alot more often than they do now.