'blocking' time in firebug

[cui]

Hi all,

    As is seen from the breakdown waterfall graph provided by firebug (i.e. version 1.7.x), there are sometimes 'blocking' time for some requests. I am wondering that:

    during this 'blocking' time period, the HTTP header is available to be looked at or not?

    and do you use the time period betweeen events of 'http-on-modify-request' and nsIHttpActivityObserver.ACTIVITY_SUBTYPE_REQUEST_HEADER as this 'blocking' time?


thanks a lot for some explaination
best regards
cui