Lost rankings on google.com, but not UK or AU

[stiwads]

I have lost my ranking for USA im not ranking for < two very inporant keywords > is google banned site for particular keywords?

we are ranking good in UK, Australia and other countries. we were on 7th position for one search & 13th position for the other search on Google.com. Still not able to recover ranking :( please help me.

i have done 301 redirection on one month back for www.

[edited by: tedster at 8:35 pm (utc) on June 2, 2009]
[edit reason] removed personal urll and specific keywords [/edit]

[tedster]

Hello stiwads and welcome to the forums.

Indeed this does happen - penalties or ranking demotions can be applied to just certain keywords on a site, and sometimes you only notice this on google.com.

One reason might be the "over optimization penalty" - sometimes called the minus 950 penalty [webmasterworld.com]. Have you dig down through the search results to see where your url now appears?