Lukas,
I do not want to "muddy the waters" in this thread but I might as well post my observations here since I have already done so somewhat earlier.
We have seen a number of earlier posters report that "avast maintains connections after I have terminated Firefox".
Let me say in regard to my earlier postings in this thread I now understand what I was seeing - that, whether avast is used or not there is a significant difference in connection handling between Firefox and IE in connection maintenance that may lead users to believe avast is involved when all they are seeing is the effect of the design differences between the IE and Firefox browsers.
To the best of my ability to test in the past few days the situation is this:
With IE(7) connections that are not actively used are terminated by IE by default after (I believe) 60 seconds - I have not tested rigorously - it may be as long as 90 seconds but no longer
With Firefox(3) connections that are not actively used are terminated by Firefox after 300 seconds (the default setting).
Let's be clear, in the case of both browsers the connections are usually terminated earlier if the browser itself is terminated. With the Firefox browser there is an exception.
Due to the sluggish start up of the Firefox browser a number of Firefox users avail themselves of the Firefox Preloader function. This start up loads Firefox at start up and makes it permanently resident in memory to speed up subsequent use. A side effect of this action is that any connections made by (or on behalf of) the Firefox browser will live for the full 300 seconds (of the Firefox default) even when the user believes that a Firefox session has been terminated ... but, in fact, has not because Firefox is still resident. Even without the use of the Firefox Preloader the same situation prevails if the user maintains multiple instances of the Firefox browser and connections will only be disconnected after 300 seconds or the final termination of the last Firefox session, whichever is earlier.
Anyone care to explain this to the "average user"?
BTW this post is not intended to explain or ignore the issue raised by billman1037 but to provide some clearer explanation of my earlier postings and some insight into the postings of earlier contributors in the forum. This research shows that I cannot despite my efforts, in any way, reproduce the problem that is the subject of this thread.