Avast turned off, network connections turned on and off to see the difference, no firewall running.
To me it seems like it might be related to Codemeter accessing the hard drive. There's this distinct hard disc noise at the end of the freezes, and the first freeze I get after double-clicking the SB shortcut just before the first windowed screen appears.
So after SB up and running, I ran the resource monitor in the background, entered the scenario editor and did not do anything except wait for the piep piep of the hard disc. Then I took the attached screenshot: Codemeter writing something ("Schreiben"). This happens every two minutes now as I am typing this lines and SB running idle in the background.
Thanks,
vils