You can't preload each slide separatly in Captivate unfortunately. The only solution that I see is to use a Flash loader on each slide to load the relevante slide.
Basically you could use your Captivate project as a "Master project" that only contains Flash Loader files. The loaders will the load the relevant Captivate SWF at run-time. This would allow your master project to be pretty small and preload each SWF before playback.
Of course this would require a custom Flash loader or a Loader Widget to handle the loading of your Captivate SWFs. It would also result in you having a large number of external files since all the Captivate slides need to be published separatly.
Thanks - that's kind of what I thought, (and I did find a way to create all of the separate slides, but I think much more trouble than it's worth in the long run). I was able to get it to preload much faster by experimenting with the export settings (a combination of making the overall dimensions smaller, tightening the compression settings, etc.) One of the biggies was shortening the percentage of the preload before opening from 100% down to 30-40%...
It seemed (in this instance, anyway) that 30% was enough of a loaded buffe rfor the remainder to continue to load while the presentation was playing. Everything combined brought the file size from 15mb down to 5mb, and the percentage loaded element helped reduce 90 second preload on a cable modem down to 8 seconds - much better...!
Thanks for your input,