No doubt there's a screamingly obvious answer to this, but I'm going to ask it anyway..........
In LR under Edit/Preferences/External Editing/Edit in Photoshop CS 6, I have chosen ProPhoto RGB as my colour space.
Now, if I save out a file and open it in CS6 and choose Edit/Convert to Profile, the Source Space is given as Adobe RGB (1998).
Why isn't the Source Space ProPhoto, since I (assume) I saved the file from LR in this space?
Apologies in advance if I'm missing the obvious.