My Speed Limiter now always soon turns itself off. v6.34 build1886
In Options|Network... Speed Limiter is checked, and Speed Limit Time-out is not checked.
If I manually invoke the Speed Limiter (using either the Status Bar switch, or the Menu Bar's 'hand' symbol) it turns on for a few seconds then turns itself off again (and resumes "Full Speed"; even if I've clicked on a row in the Download tab to make sure the window's 'focus' is unrelated to the Speed Limit buttons).
Restarting Newsbin doesn't help.