Beta 4.9.1 just locked up. Zero cpu use at normal priority, and nothing is preempting it. The UI is dead. There's a console open and the odd IO exception message appears, but there's no functioning user interface and, apparently, no network activity.

All I did was start it up, sort the downloads by Status, select the final queued item, and then surf elsewhere; when I came back to it it was like this.

What gives?

The LW UI going dead is not unusual; its going dead without 100% CPU activity is.