Hi all! I've got a MK-RC7 (or RF-602) wireless flash trigger from LinkDelight, and it doesn't work with my Nissin Di622 speedlight, but it works fine with my friends 430EX II. My Di622 works fine on my camera and on the off-camera cord when the cord is attached to my camera. However my flash won't work on the MK-RC7 receiver, nor on the off-camera cord with the cord attached to the MK-RC7 receiver.
The receiver's cable output port works fine for triggering the camera and the studio lights.
I thought the receiver's hot shoe wasn't working and was about to send it back until I tried the 430EX II!