In reply to andyd1970:
Have you tried gently bending the vertical tabs at the front to match the boot better? My ultras are quite narrow in the toe (sounds like the Jorasses are too?) and I had to adjust the tabs on my G12s a little for a good fit, but now I have no problem with the fit. They do need to be done up reasonably tight though for the toe basket to sit tight with no gaps.
Perhaps a pic to see exactly? Would be a shame to buy a new set of crampons if the issue with your current ones could be fixed.
Though I am sure someone with your combination of boots/crampons could offer more specific advice.