De-Index Google??

[Theeban]

One of my client had created a web page and it was indexed, the web URL was named aaa.html. After few days he changed the name to a-b-c.html. Then without considering changes, got links for aaa.html, then again he changed name to aaa.html.

However, Google indexed a-b-c.html on 17 Jan 2012, but now when I checked index date, Google shows me 15 Jan 2012. I am using SEO Quake on firefox.

Is it kind of penalty??

Even, I had seen the site on page 2 on Google and page 1 on Bing, but now the ranks are lost....

Note: It is new site, and we are getting daily quality backlinks and keep on pinging.


Any suggestions/comments?