Try running a dedicated grounding wire to the outside of your spark plug - I agree it could be a grounding issue.
Also, take your plug wire and snip the ends so there are fresh segments for the coil and boot to thread into.
Orrr... you can just wait for your parts to get there.
I've had several bikes now spark on the case and no sparky sparky in the cylinder - worth a shot.
What's your voltage going into the HT coil? (edited)