thread safety question

Hi,

  Can anyone explain to me the cuase for the following console message

!!!!! XPConnect wrapper thread use error...
  XPConnect WrappedNative is being accessed on multiple threads but the
underlying native xpcom object does not have a nsIClassInfo with the
'THREADSAFE' flag set

  I'm having a thread listening to network messages, which suppose to open
an alert window, by using an XPCOM object implemented in JS.

  Any clue will be appriciated,

  Mark.