Having getting problem PR0 from PR n/a

everytime i made a site, i happened to get PR 0 from PR n/a just in one week but from this month (month) i noticed that i didnt got even PR0 the site i made from the mid of previous month
anyone happened to know then please share,
is this any update of google or what ?

You can overkill your site with hard seo. Do you do?
Another reason for deindexing is copy/paste content.

Try to ping your site. I had the same problem with one of my sites.
After the ping site was alive again.

no i just manually done smooth SEO and i already ping up the site, and content are unique, i wrote by my own and one thing more, site is ranked on google second page but had PR n/a
stange isnt