I discovered my problem and recovered my bitcoins! I initially installed Bitcoin-Qt under my user (no admin privilege) login. The installation had an error that lead me to believe that I needed admin privilege. I logged in as administrator and installed without problems and then transferred my bitcoins and logged out.
I later logged back in as user, and this user account had a short cut to Bitcoin-Qt from the bad installation. Forgetting that I had installed under a different administrator account, I clicked the Bitcoin-Qt, it started and when it finally synchronized it had also created a new wallet address. My original wallet address was still under my administrator login.
I didn't realize my problem because I rarely login as administrator and when I investigated the block chain it looked suspicious to me. When I did finally login as administrator, I realized my problem.
Thanks for all the good responses and information. No files had been deleted and my wallet was not compromised and nothing lost.
I do believe there are installation issues however. If the user needs admin priv, it should pop up and ask the user to login as administrator.
Also, as a test, I tried installing under a third non-admin account that also failed. And with this failure, somehow I now have error messages with the Bitcoin-Qt under my administrator account. I don't believe files are properly separated between users.
I believe I am going to uninstall completely and only install one version again under administrator.

I installed Bitcoin-Qt wallet on my Windows 7 PC on 12/1/13 and transferred 0.3 bitcoins from coinbase this wallet. I then transferred 0.2 bitcoins from this wallet to cryptsy. According to blockchain.info   https://blockchain.info/en/address/1BvHrxNdPdzfUAu9YH9QmwRYoJf5YGuWrN
not only did 0.2  bitcoins transfer to cryptsy but my remaining balance 0.1 bitcoins was also transferred to an unknown address. At the time I didn’t realize what had happened because my wallet showed a correct balance of 0.1 bitcoins. Believing that everything was working correctly I then transferred another 7.7 bitcoins from coinbase and transferred 6.8 bitcoins to cryptsy. And again the same thing happened -- my remaining balance of 0.9 bitcoins was sent to another unknown address. My wallet continued to show a correct balance of 1.0 (0.9+0.1) bitcoins so I suspected nothing. I only discovered the problem when I closed my wallet. When I reopened the wallet it took more than half a day to synchronize and when competed my wallet address changed to a new address with a zero balance.  Do I have any recourse in recovering my lost 1.0 bitcoin? My lost bitcoins can be seen at the unknown addresses with blockchain.info and they have not been spent/transferred yet.

I purchased bitcoins from coinbase several times without problems. My only problem with them was when I tried to verify my credit card. Coinbase emailed me that small charges had been made but I couldn't find them so I can't verify, and they keep sending me emails reminding me to verify.

After closing, I reopened Bitcoin-Qt wallet, it went through a long recovery process. It is now working again but I have zero balance and no transactions. Since I just started using I had not made a backup. Is there anything I can do to recover? And if I am running a risk by closing the wallet, why doesn't it warn me to backup? In the future should I backup after every transaction?