Well, I admit I didn't explore the problem either

There are 2 things I'd like to note, however:
1. The files with the arguments cannot be stored in cache as they are, because the question-sign character cannot be a part of the filename. So, it must be either encoded somehow (%3f maybe), or replaced. Therefore I asked how they are stored.
2. When the server sends a HTML page to your browser, it may set a "don't cache" flag in the HTML headers. Such a file may not be written to disk (at least it's not supposed to, I guess; the Internet Explorer behavior is another thing, of course) - so, I wouldn't be suprised by the fact that some pages are not scanned (on disk).