COM interop and remoting events

Hi all.

I have a DLL exposed as a COM object which contains a class.
This class is instantiated and used by a VB6 Windows Form.

This class calls methods on a remoting singleton object which on turns
sends events.

These events are catched by my DLL which on turn launch events to the
VB6 form.

Events sent by the singleton are handled by my DLL in a thread which
the .NET clr extracts from the thread pool.

The problem is that this thread is not the same as the first which
makes the call to the singleton.
For this reason the VB6 form is not able to answer the event and
application hangs.

Is there a workaround?

many thanks in advance