Maybe u didnt do it correctly - i have had no problems. here is a sequence u can follow.
Insert your SanDisk Cruzer into an available USB port on your computer.
Select "LaunchU3.exe" from the autorun dialog box. If autorun does not begin, open Windows Explorer, navigate to the flash drive and double-click "LaunchU3.exe."
Close the AutoPlay dialog box. Click on the U3 icon in your system tray (lower right of computer desktop).
Select "Enable Security."
Enter a password in "New password" and "Retype password." Enter an optional hint, if desired. Click "OK."
Download "SecureAccess" from SanDisk's website. Select either the PC or Mac link.
Unzip the file you downloaded to the root directory of the SanDisk Cruzer.
Double-click the unzipped file on the removable drive. Select your desired language from the drop-down and then enter your desired password twice, using at least six alphanumeric characters. Optionally, enter a password hint.
Read the EULA (End User License Agreement) and then click "OK" to accept.
Drag and drop files onto the main SecureAccess screen. Alternately, you may copy and paste files onto the main screen, drag and drop file onto the vault icon that is now located on your desktop or click the "Add files" button to browse and add files. Click "Add Files" or "OK."