Random AV built using in AdvStyleIF

I just rebuilt my MDI app with component pack (BDS2006) and now it generates random access violations when opening a MDI child window that uses TMS controls 

I try to open the window it generates the AV, try again AV, try again then it opens OK.
Using the MAP file to lookup the address I have traced it down to the AdvStyleIF ThemeNotifier RegisterWindow unit class and method.
procedure TThemeNotifier.RegisterWindow(Hwnd: THandle);
  if Assigned(RegMonitorThread) and not RegMonitorThread.WinList.HasValue(Hwnd) then  <-- Break point here, this line generates the AV
    RegMonitorThread.WinList.Add(Hwnd);   <-- Never gets to this line
Any idea what has changed to cause this?

Something to do with AutoThemeAdapt as turning this off seems to fix the problem on a one test page. 

Could you please send some sample source app by email with which we can reproduce this so we can investigate this as it is unclear how you use the components and thus, how we could reproduce this and investigate it.