Does it matter what orientation the camera is set on the scope?
I wondered if VPhot can correct for errors from N up as CCD charts are set to.
I never saw a button for plate solving.
I know that WCS indicates the plate solving status.
Does it do it automatically then when you upload animage or at some other point under the bonnet?
No separate button for plate solving. It's done when the images are processed after you have uploaded them. If the images are already plate solved, then it doesn't do it a redundant second time. The AAVSOnet folks much prefer if you plate solve them yourself before you upload them to VPhot because the plate solving can take a while and slow the queue down substantially when things are busy. The processing time on the cloud is an expense for the AAVSO as well so if you plate solve them yourself before upload, you save the organization some money.