caching flash files

when does a browser use the cache?

[benlieb]

Usually the first load of a flash file takes longer than the rest, since it is in cache for subsequent loads.

I don't know how many of you are familiar with passing variables to _root via a query string like this:

<embed src="media/banner.swf?section=office"

making a variable _root.section equal to "office"

Anyway, I'm concenred that adding a query string might force a re-load even the the actual file hasn't been changed. For example would the following cause the flash file on page_y to be totally reloaded, or used from cache, since the query string is different:

page_x:
<embed src="media/banner.swf?section=office"

page_y:
<embed src="media/banner.swf?section=treatment"

It seems to behave differently on different systems, and it's hard to know what is a slow connection, and what is a re-load of the whole movie.

Any experiences/help is appreciated