User Capability Issues

Hi, I am having issues with users on my site http://www.tilt.nz

I have a role that originally had 288 users assigned to it. It then seemed to glitch(?) out randomly and now doesn’t have a name and I cannot edit or delete it, I also cannot revoke the role from the users. So at the top of the dashboard it just says (288) showing the original users are still assigned that role, however when I look through all the users, none of them show that they are assigned that role. And all of the users who were originally assigned the role suddenly couldn’t gain access to the site – so the role had obviously stopped working.

So I have made a new one with the same capabilities, but I would still like to delete the one not in use – is this possible?

Thanks in advance,

Tawny

The page I need help with: [log in to see the link]