Just few days back, early morning I have been casually checking the stats of my sites and upon opening one of my sites through a search phrase as to see whether Search Phrase has been justifiably providing necessary information I was stunned to see the decreased green-bar above. Google PageRank for my site kashmironline.net had been reduced to just 3. It was really panicky for me and i was left scanning my recent changes to the site. Upon further digging i was surprised to see many of the pages and subdomains on site that had low PR now having better greens. Also i noticed many of the sites that previously had low PR were ranked better. Since then i had been trying many a things and visited my favourite communities and forums but to no avail. Just today while logging out of statcounter I thought of visiting here. I want my Net-brethren to help me if there is any way that helps me to know what wrong could be with anything on the site which causes abrupt fall in PR. Does any of the webmasters here experience the fall in PR? And if "yes" please share your information !
Have you sold links on that site? Google is giving penalties for sites that sell links... On the other hand - it could be just a hiccup, and you might get the PR back soon (if that doesn't happen within a few days, then it's not a hiccup)
If you drop rapidly in Google you will have a penalty against your domain - Neva buy or sell back links, If you do get a penalty you will be notified thruw webmaster tools
try to concentrate on your work and try to get good quality back link as soon as possible B'coz I thing you lost your some quality back links may be that is the reason.