I agree. well obviously I have experienced the same problems otherwise I wouldn't be here reading this... so here goes what I did to think the problem was ME and not google. However, I do belive that G has implimented something new to catch certain issues.
For example. On one of my sites, the home page of that site USED TO BE a 5/10PR and droped to PR0 along with most of my traffic. Now the weird part is that the other sub pages are still hanging around PR4-PR6.
SO.. the only thing I can think of is this: This website that I am talking about is PPC with your typical gazillion "Popular Searches" organized nicely on the home page...
What I am thinking is that G no longer wants to see all of these NON-Relative links... That's my guess. I have also done some other SEO stuff and reading this thread has got me wondering if possibly the other
things that I did were a factor, but no - because the subpages are still fine (knock on wood).
Some interesting stattements from this thread that got my attention were:
1. "spamming the same word phrase in multiple instances"
2. optimizing meta-tags / doing SEO stuff and G not liking that to give the "little guy a chance"?
SOLUTION: diversify! more than one website and dont marry G - promote to other well know SE's!
A-MEN to that quote...