Moved Down over 100 Places - Penalty or SERP Changes?

[guru84]

Hello,
I noticed this morning that my site had moved for its main keyword term:
Google.com (non-US) - from 11 to 105
Google.com (US) - from 29 to 325

However on google.com.au my site was before and still is number 1.

Unless I can fix this my life is pretty much over as my website is where all my income comes from so I thought maybe someone could tell me if this is a penalty or just SERP changes. Seems to me to be a too dramatic drop to just be SERP changes. I have been working with, supposedly, one of the best SEO firms, and as far as I know they are white hat. I stopped using them after 3 months because of the lack of results and all the links they picked up seemed to be from low quality directories. Of the 100s of links they got GWT only picked up about 10. Could this be a factor?

Any other ideas on what I should do? Any help would be very greatly appreciated.

[tedster]

I agree, a 100 position drop is not likely to be a shift in the algo - especially if it's not shuffling other sites in any drastic way. That much trouble is almost always a penalty, and almost always related to links.

Do the backlink research, clean up what you can, explain the situation and ask for reconsideration.