Imagined Tones--what a creative name! I get the
feeling I know what you're talking about, and I'm also presuming you've set your SL cache to the current maximum allowable size in PREFERENCES ---> NETWORK of 1000MB.
If you have a detailed repro I can go through as well, please post about it in
Technical Issues, and discuss with other Resis. Things like this should be stepped through so I have a better understanding of what you're seeing.
The SL cache in general doesn't remember things very well for me, unless, say, I am just going from the Welcome Area to Waterhead's Hidden Lakes facilities, and back and forth again. But multiple locations as you describe, it takes time to download again. :\
When you go somewhere that uses many intensive textures, for example,
Bedazzle Studios (filmset of
Golden Bells and Silver Spurs, to give more context), or, heck, a texture store--the "scene memory" used may be clearly over 100MB. Going to several stops like this quickly adds up, as you can see. And the old content--textures, sounds, object data--will be rotated out of your cache.
An effective thing to do right now is detail your experiences further, provide a list of steps others can follow (which coordinates, how long you stayed at each one, etc.), also play in
Preview 1.9--and if the cache isn't working as you expect it to, share your experiences about that and send a bug report too.