It's not a permissions or disk issue Colin - I've repaired everything and it makes no difference.
Basically if I try and drag an object around my Environment, when I let go of it it leaps about 3 screenwidths to the left or right. It makes it pretty much impossible to work in the environment. Admittedly my Environment is big and pretty complex, and uses a lot of instrument channels, Auxes and multi instruments, but it's essentially unworkable as things stand.
I'm trying to find workarounds using the Mixer window, but short of rebuilding my entire template from scratch this is going to be an increasingly big problem for people who are migrating from Logic Pro 9 or earlier. Clearly I'm not the only one with the problem, so hoppefully it'll get passed up the line and looked at.
Jules