nt10000 - 11:56 am on Nov 24, 2011 (gmt 0)
Yes I've seen traffic throttling on some of my sites too. A new day starts and I get great traffic for several hours then it stops suddenly until the next days starts, then the same all over again. The traffic numbers are very close each day before they get switched off. I've seen this happening on and off for years so it's obviously another mystery in the Google algorithm, nothing to do with Panda.