Is it an older Axis or one of the newer Axis Tributes? I ask because a number of people including myself have complained about difficulty installing the D-Tuna correctly on the Axis Tributes. They have a re-designed Gotoh which could have messed something up but I'm not sure what. I have a number of Axies, on all of the older ones there is zero problem, on my Tributes only one of them works half-assed and I gave up trying to install the D-Tuna on the others. Some point too far down and one of them only gives me a half step like you are saying. Weird and annoying.