Director FAQ [9] Text & Hypertext [9.11] Whats the deal with scrolling text set to background transparent?
Rather alarmingly, using any ink other than copy for a scrolling text field, the background will scroll along with the text and new lines of text scrolling into view will display with a plain white background. This is what’s known in the trade as a bug. The only way I can see to avoid this is to create your own custom scrolling field script as in 9.10 above.