Hello @gert_mogensen,
Thanks for contacting us regarding this issue. The CPU on the laptop is quite under-powered as you have noted, it would be a good first step to make sure that your hardware meets our recommended specifications moving forward.
As for the other points you mentioned, I would also update your Node 2 to the latest firmware version and confirm weather this issue occurs with the Node 2 not in the mix. Just so you are aware, there have been a few reports of Bluesound syncing issues and we are working directly with Bluesound to resolve these issues, you can take a look at this thread for more information.
Thanks,
Noris