MySQL workbench -"Could not decrypt password cache"

In MySQL workbench, whenever I open a new connection, a message "Could not decrypt password cache" popup.  To let this message, go to
to C:\Users\your_username\AppData\Roaming\MySQL\Workbench\
 delete workbench_user_data.dat

In my case, I login as Administrator, go to  C:\Documents and Settings\Administrator\Application Data\MySQL\Workbench, delete workbench_user_data.dat

Restart MySQL workbench. Enter  password and check save password in vault. The message  "Could not decrypt password cache" will not appear.

Reference:
http://forums.mysql.com/read.php?152,389642,404404