Delay in application

Hello,

in Feb 2009 I applied as a skilled worked.
My processing office - Buffalo.

In Feb 2010 additional documents were requested. I submitted those I had and notified of the absense of the rest.

In March 2010 - received medical forms. Passed in May 2010.

In Nov 2010 - received again a request for the papers i didnt have back in Feb 2010.
At that point I submitted what I could, with the last package being sent in Jan 2011.

I have not heard from the VO since November 2010.

When I send Case Specific Inquiry - I get no response.
When I send Generic Inquiry - I received a response: We requested background information from other government office(s). Can not provide the completion date for your application. Thank you for your patience and keeping the correspondence to the minimum.

PLEASE!!! Advise me!! What information might have they requested?
How can I facilitate the process?

And what should I do at all?

The processing time on cic.gc.ca for my time-frame applications is set to be 19 mnths. and for me it has been 29 mnths.

THANK YOU VERY MUCH FOR YOUR HELP!