First, I want to thank you for using the correct term of translucency........ I'm getting tired of people talking about the new 'transparent' titlebars in WB5, when we've had transparency for years.
You shouldn't have to 'do' anything, if you're using WB5, and one of the new skins designed for it (assuming your machine has the proper graphics card, and drivers).
What does it say when you click the Troubleshooting link in the WindowBlinds Configuration dialog?
Is the "Never use per pixel borders on a skin" checked by chance? If so uncheck it, apply changes, and see what happens.