nsIXPConnect interface unavailable in Firefox 3.5 ???

[Sébastien Lorquet]

Hi,

This time my question is about extensions :)

I'm developing an extension for ff 3.5, and I want to access the
nsIXPConnect interface to access its javascript related fields.

I then use:

nsresult nr;

nsCOMPtr<nsIXPConnect> xpc = do_GetService(nsIXPConnect::GetCID(), &nr);

NS_ENSURE_SUCCESS(nr,nr);

the problem is, this call returns nr NOINTERFACE, which throws a js
exception in my webpage:

Exception: [Exception... "Component returned failure code: 0x80004002
(NS_NOINTERFACE) [MyInterface.myMethod]" nsresult: "0x80004002
(NS_NOINTERFACE)" location: "JS frame ::
file:///C:/sources/trunk/ext/client/init.js :: anonymous :: line 74" data:
no]

why can't I access this interface?

regards
sebastien