Anti-alias for Readability Issue

The issue is this…

Viewed on a PC with 16bit colour…

When using dynamic text boxes with “anti-alias for readability” turned on (Flash 8), the background of the textbox shows like a 5% white alpha when used on a dark background.

The problem is not seen when the screen is set to 32bit, or on a mac at 16bit or 32bit colour.

Anyone seen this before or have any ideas how to fix it?

Thanks.