PETITION FOR A NONIMMIGRANT WORKER was processed and mailed to the address on record

Hi,

I am fresh H1B applicant. On May 7th 2014 I got the receipt no. On may 16th RFE received.

8th aug RFE was responded and on 20th August the status on USCIS site is “Your Case is approved”.

Now on 28th Aug my status got change three times.

  1.   Case Status: Card/ Document Production
    

On August 28, 2014, the post office returned your document I129, PETITION FOR A NONIMMIGRANT WORKER as undeliverable.

After few hours the status was:

  1.   Case Status: Initial Review
    

On August 28, 2014, your Alien Registration Number was changed relating to your I129, PETITION FOR A NONIMMIGRANT WORKER

And finally it is

  1.   Case Status: Post Decision Activity
    

On August 28, 2014, your notice I129, PETITION FOR A NONIMMIGRANT WORKER was processed and mailed to the address on record.

I am confused now what does it mean. Is there any technical glitch on USCIS site or something wrong.

Please help me.

Thanks.