You should send an email to the customer with passfix.exe attached and the instructions below.
Here are instructions that you can copy and paste in the email you send to a customer:
Attached with this message is a file called "passfix.exe." Please double-click this message in your inbox list to open it in a new window. At the bottom of the window you will see an icon that represents passfix.exe. Save passfix.exe by right-clicking on it and choosing "Save As." A window will open up asking where you wish to save it to...click on the yellow folder with the left-arrow pointing up repeatedly until it says c:\windows\desktop in the location window, and then click OK or Save.
Now close all open windows and programs. You will now have on your main desktop screen a new icon labeled "passfix." Double-click on it and follow the onscreen instructions.
Once the passfix program has finished, restart your computer. Then double-click the My Computer icon, then double-click on Control Panel, and double-click on "Internet" inside the Control Panel. Then click on the "Security" tab (for IE 4, the "Content" tab). You will see an area labeled "Content Advisor." Click the button that says "Disable Ratings" (if the button says "Enable Ratings," do NOT click it ... you are already fixed), and when it prompts you for a password, just leave it blank and click OK. If another "Ratings" window opens up, just click OK at the bottom. This will turn off Content Advisor and this should solve the problem.