Darn it if I don't have some flickering from fluorescent lights in indoor footage from Japan -- shot with both my Canon XL-H1 and Sony HDR-HC1. This was both in footage shot in 60i and 30f -- with shutterspeeds of 1/30 and 1/60.
What is going on? While the United States is 60hz and Western Japan (where I normally stay) is also 60hz, eastern Japan including Tokyo and Hokkaido is 50hz. This means that I should have used a frequency multiple of 25/50 instead of 30/60. So the best shutterspeeds for avoiding flicker were 1/25, 1/50, or 1/100.
Let that be a lesson to me.
p.s. In my defense, it's very difficult to see flicker in the little LCD viewfinders, it's only visible when you view the footage on a television monitor.
Here's a great guide to electricity voltages and frequencies of the world: http://www.kropla.com/electric2.htm
and here's a great guide to flicker-free shutter speeds depending on the frequency: http://www.cinematographyelectronics.com/index_flickerfree.html