URL Only: The Why Me? Checklist

Why are my pages going URL only

[NoLimits]

I would like to hear opinions on why some pages of sites go URL only.

If you have recovered from a URL only disaster, please share how you overcame it.

This is my checklist to begin with, please correct me if I'm wrong on anything:

- Duplicate Pages
- Hijacked site
- URL Problems (which I would love specifics on)

On the URL side of things... for a dynamic URL, should one use index.php? eg.. domain.com/index.php?article=25 - or is it better to use domain.com/?article=25, or something else completely?

I'm trying to correct whatever it is that is causing my site to lose well listed pages to the URL only disease... that seems to be spreading throughout my site like a virus. The come, they go - they come back again, they go again. Different ones each time. Currently about 40% of my unique content is URL only.

Any ideas, suggestions,things to check, anything - greatly appreciated.