I rolled back to the 4.0.6 version and the difference is that in the 4.1.0.1 version I see a slew of CSS warnings in the Web Inspector:
[Warning] Invalid CSS property declaration at: * (tribe-events-theme.min.css, line 1)
[Warning] Invalid CSS property declaration at: * (tribe-events-full.min.css, line 1)
[Warning] Invalid CSS property declaration at: * (tribe-events-full.min.css, line 1)
[Warning] Invalid CSS property declaration at: * (tribe-events-full.min.css, line 1)
[Warning] Invalid CSS property declaration at: * (tribe-events-full.min.css, line 1)
[Warning] Invalid CSS property declaration at: * (tribe-events-full.min.css, line 1)
[Warning] Invalid CSS property declaration at: * (tribe-events-full.min.css, line 1)
[Warning] Invalid CSS property declaration at: * (tribe-events-full.min.css, line 1)