Auto-update only happens after you confirm that you want to auto-update, with the following dialog:
http://www.ipisoft.com/images/autoupdate.pngWe performed additional verification recently to make sure this works as expected.
Could it be that you overlooked this dialog?
You do not need active internet connection to start iPi Studio. I have iPi Studio on my laptop and I regularly use it on the go, without any internet connection. You only need active internet connection during installation of iPi Studio (even if you already have .NET Framework and other prerequisite components installed).