For some reason there are a couple of projects that will come back every time I delete them. They are labeled “Nov 2012 Photo stream” etc. They will come back after I relaunch Aperture and it doesn't matter how many times I delete them. There are no photos inside these projects each time. Any ideas?
You have Photo Stream enabled in Aperture’s preferences with Automatic Import checked. Aperture monitors your photo stream and if any new photos appear they get automatically imported into monthly projects named as you describe.
If you disable the “Automatic Import” option I believe Aperture will stop creating those projects. Select Aperture->Preferences and click the Photo Stream icon at the top. Uncheck the Automatic Import checkbox.
Thomas