xpcom_core!NS_DebugBreak_P(unsigned int aSeverity = 1, char * aStr = 0x03accf60 "XPConnect is being called on a scope without a 'Components' property!", char * aExpr = 0x03accf58 "Error", char * aFile = 0x03accf00 "c:/home/mozilla.org/comm-central/mozilla/js/src/xpconnect/src/xpcwrappednativescope.cpp", int aLine = 764)+0x2a4 xpc3250!DEBUG_CheckForComponentsInScope(class XPCCallContext * ccx = 0x0012e848, struct JSObject * obj = 0x04a60c40, int OKIfNotInitialized = 0)+0x89 xpc3250!XPCWrappedNativeScope::FindInJSObjectScope(class XPCCallContext * ccx = 0x0012e848, struct JSObject * obj = 0x04a60c40, int OKIfNotInitialized = 0)+0xbd xpc3250!GetContextFromObject(struct JSObject * obj = 0x04cc29c0)+0xc2 xpc3250!nsXPCWrappedJSClass::DelegatedQueryInterface(class nsXPCWrappedJS * self = 0x05152940, struct nsID * aIID = 0x020ec5cc, void ** aInstancePtr = 0x0012ea74)+0x11d xpc3250!nsXPCWrappedJS::QueryInterface(struct nsID * aIID = 0x020ec5cc, void ** aInstancePtr = 0x0012ea74)+0x13b xpcom_core!nsXPTCStubBase::QueryInterface(struct nsID * aIID = 0x020ec5cc, void ** aInstancePtr = 0x0012ea74)+0x4b xpcom_core!nsQueryInterface::operator()(struct nsID * aIID = 0x020ec5cc, void ** answer = 0x0012ea74)+0x2d gklayout!nsCOMPtr<nsIControllerContext>::assign_from_qi(class nsQueryInterface qi = class nsQueryInterface, struct nsID * aIID = 0x020ec5cc)+0x19 gklayout!nsCOMPtr<nsIControllerContext>::nsCOMPtr<nsIControllerContext>(class nsQueryInterface qi = class nsQueryInterface)+0x34 gklayout!nsGlobalWindow::ClearControllers(void)+0xb8 gklayout!nsGlobalWindow::SetDocShell(class nsIDocShell * aDocShell = 0x00000000)+0x290 docshell!nsDocShell::Destroy(void)+0x461 appshell!nsXULWindow::Destroy(void)+0x40a appshell!nsWebShellWindow::Destroy(void)+0x14f appshell!nsWebShellWindow::HandleEvent(class nsGUIEvent * aEvent = 0x0012ee48)+0x371 afaict, in this case we cleared the Components object too early

it's remotely possible that mailnews is foolishly setting the control w/ code from a different window....