I am using the HD100 MKII head with an old crate blue voodoo 4x12 slant cabinet. The cab has celestion green backs installed. The problem is the most bizarre thing I have ever seen. At moderate volumes the 4x12 will spit the 1/4" cable out the back of the cab. It tends to happen when the cab is flat on the floor without the wheels installed. Any thoughts on why this is happening. I have used a marshall tsl60 through this cabinet for years and never had this problem before. Any thoughts on this??? Thanks!