This has been a persistent problem since 2006. The ibeam
cursor in Flash textbox, when used in Director disappears at its
own will. End-users of applications get really frustrated as they
get lost in the dark.
I truly believe the best multimedia applications can be
created using the Director+Flash combination. I do hope Adobe can
see this as a major USP and improve Director-Flash integration. It
will go a long way in staying sustainably competitive.