[VISTA] DestroyWindow() changes ?

I'm facing a puzzling bug with a ShellFolder Extension on Vista.

the explorer crashes when I leaves a view (IShellView) provided by my
extension - a classical view with one ListCtrl child inside.

I process the IShellView::DestroyViewWindow() as follows:

UIActivate(SVUIA_DEACTIVATE); // ok
DestroyWindow(myViewWnd);
myShellBrowser->Release();

under 2003, DestroyWindow(myViewWnd) (win32 API) will cause the
following MSG to be dispatched to my windowProc:

WM_SHOWWINDOW, SW_HIDE, 0
WM_WINDOWPOSCHANGING, 0, nnn
WM_WINDOWPOSCHANGED, 0, nnn
WM_DESTROY, 0, 0

WM_NOTIFY : from: 202AC, id: 1000, code: LVN_INSERTITEM) (insert ??)
WM_NOTIFY : from: 202AC, id: 1000, code: LVN_DELETEITEM) (I indeed have
WM_NOTIFY : from: 202AC, id: 1000, code: LVN_DELETEITEM) 2 items)

WM_NCDESTROY, 0, 0


so far, so good.

under Vista, I do have:

0x0090 (????), 0, 0
WM_SHOWWINDOW, SW_HIDE, 0
WM_DESTROY, 0, 0

WM_NOTIFY : from: 501C0, id: 1000, code: LVN_INSERTITEM)
WM_NOTIFY : from: 501C0, id: 1000, code: LVN_DELETEITEM) correct return!

** explorer.exe crashes **
** no other msg received **

it may look like a delayed booming but it crashes always after the same
MSG, OOH I can't figure out why explorer doesn't enjoy my
Notify:LVN_DELETEITEM handling -- if do nothing!, my windowProc just
returns 0.

thanks for any tips !!

Sylvain.