Slow death still Happening?

Are sites still having an issue with this?

[Harwich]

I have read many posts from the last several months discussing this issue but nothing recently.

My site just started having this issue around 5/22.
Google went from spidering 20 to 200 pages each and every day to now it comes by every 3 or 4 days and grabs a couple deep pages. I went from over 600 pages(the whole site) indexed to about 300 and I assume those will continue to drop. Traffic has dropped by about 50% as well. Has anyone discovered the cause of this? I am assuming it is a google glitch or some sort of penalty but I have no idea what for. My PR has not dropped in fact in this last update a few of my pages went from PR5 to PR6.

I have double checked my robots.txt
No server down time.
No site design or navigation changes.

Any thoughts?

Thank You
Harwich