i had a similar kind of problem on my windows 7 64 bit version. Some gadgets disappeared and the clock turned black. After a long time found a solution.
Deleting the Zone setting from Registry can help fix the Gadgets issue.
1. Open regedit and navigate to the following key: HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings Here, delete the Zones Key
2. Restart the Computer and test it
it worked for me..check it out and let me know!!