What's wrong with WS_EX_LAYERED and WS_EX_COMPOSITED?

From MSDN:

WS_EX_COMPOSITED

Windows XP: Paints all descendants of a window in bottom-to-top painting order using double-buffering. For more information, see Remarks. This cannot be used if the window has a class style of either CS_OWNDC or CS_CLASSDC.

WS_EX_LAYERED

Windows 2000/XP: Creates a layered window. Note that this cannot be used for child windows. Also, this cannot be used if the window has a class style of either CS_OWNDC or CS_CLASSDC.

Remarks

Windows XP: With WS_EX_COMPOSITED set, all descendants of a window get bottom-to-top painting order using double-buffering. Bottom-to-top painting order allows a descendent window to have translucency (alpha) and transparency (color-key) effects, but only if the descendent window also has the WS_EX_TRANSPARENT bit set. Double-buffering allows the window and its descendents to be painted without flicker.

If WS_EX_COMPOSITED is set on a dialog window (e.g. to reduce flickers from child windows resize), then, with the default XP theme, mouse hover on the minimize button or mouse down on the close button will have no visual feedback. It seems that the back buffer for the non client area does not get updated. One obvious workaround is to only add WS_EX_COMPOSITED on WM_ENTERSIZEMOVE and remove it on WM_EXITSIZEMOVE.

What if WS_EX_LAYERED is also set? The above workaround will not work, and worse, the client area will have all sorts of update problems: edit window will not show or receive blinking insertion point, push button will not show sunken/raised border on mouse down/up. Again it seems that the back buffer is not updated. Yet another obvious workaround is to only add WS_EX_LAYERED on WM_ENTERSIZEMOVE and remove it on WM_EXITSIZEMOVE.

What's next? I'm waiting to be hit by more poorly documented styling bugs.