My site only ranks with &filter=0 for one keyword

[Thaparian]

Hi folks, i need little help from you guys.

The title of my site's homepage is "Keyword1 and Keyword2"

The site has been authority for keyword1, for almost 6 months now and for second keyword it ranks on 2nd to 5th page on G.

But now, i rank no where for keyword2.
If i repeat the search with "omitted results included" (&filter=0 in the url) the rankings are same.

I didn't made any special changes to site. All i did was added a sitemap to main site and sub domains (sitemaps were added like 2 weeks ago) and moved the footer links into the sidebar (yesterday).

All other pages rank the same.

What should i do to get my rankings back?

Is it a penalty or just a glitch in Big G?

[tedster]

Is there another domain that ranks naturally for Keyword2 - and has content that is a duplicate of yours?

[Thaparian]

Site is back up. :)
Most sites in my niche has same content.