RhinoFish - 8:02 pm on Nov 27, 2011 (gmt 0)
if you're using certain redirects (that drop session or referrer data), they might also mess up page-to-page hand-offs, yielding a high bounce rate.
back in August, G changed the way they handle sessions:
good read for understanding these issues. plus, it'd be interesting to see if your high bounce rate changed when they changed session handling.