Reaching out for help. Non Novice completely stumped.

5 years ago when I started my web site it was called wedoitallconcierge.com. I figured out pretty quick that no one could spell it, so i changed it to wedoitallvegas.com. I kept the wedoitallconcierge.com as a link through to the new site by pointing the DNS to the same name servers.

Everything was fine for the last 5 years. Our site has done well and we have great rankings in google (try poker dvd). Until today, that is.

Today I noticed that many of our search engine listings in google were all of a sudden changed to wedoitallconcierge.com. A good example is a google search for 'las vegas discounts'. Until today we were #1 for wedoitallvegas.com. Today we are #5 and our listing is for the concierge url. Note that the text in the google listing says wedoitallvegas, but the url is wedoitallconcierge.

1. What the heck happened all of a sudden?
2. What do I do to correct it? I don't want to lose any rankings and I now have rankings for both sites. It did not remove ALL the wedoitallvegas reference, just many of them.

Any help would be greatly appreciated. My webmaster is as baffeled as I am. I built this site myself until it got to big to handle, so I am not a total novice in web design and promotion. This is totally new to me.

addition to post

I discovered that the concierge domain was set as a mask of the vegas domain over 5 years ago.

We have also noticed in google that our vegas site listings DO NOT have the www in the url (poker dvd search) but the concierge listings DO have the www in the url (las vegas coupons search).

Any ideas how in the heck to fix this?