C++ application with Flash UI

We are developing C++ application which has Flash based UI.
C++ part is a multi-thread application. Algorithm from one thread send data to Flash interface. MFC based application with Flash AcitiveX control is running on another thread.

Right now for exchanging data between Flash and C++ we are using technics described at http://www.macromedia.com/devnet/mx/flash/articles/flash_vb.pdf
At C++ side its a call for SetVar(“event”,…) and at Flash part its a code _root.watch(“event”,CallBackFunc)

The problem is that on big load, when in a short time a lot of messages being sent from C++ to Flash, Flash ActiveX crashes.

Are there any better and reliable ways for exchanging data betwen C++ application and Flash?