Comment 1 for bug 1389096

Maybe their network configurations were different?

Yes, well, I don't disable network access or remove existing sources, so the apt-get update command will experience long timeouts if the machine thinks it has a network (maybe when you installed it it was connected?) but isn't actually plugged in.

Could you tell me if this was the case?

I'd prefer not to completely move away the user's source files, but if that's the best option I'll certainly consider it.