We have an issue where some learners get to a slide that has a SWF video they are supposed to watch and excessive buffering occurs, in some cases learners have waited up to 10 minutes and nothing happens. I have seen where others have recommended deselecting the "Disable preloading of embedded Flash content" (it is checked by default). I have also seen where you can supposedly control the amount of slides that are preloaded but I can't find this option so I'm assuming that it is no longer an option in Presenter 11 and there is a predefined default setting? So my questions are:
Preloading of SWF content and Presenter's preloading of slides are separate things.
For slide/audio preloading Presenter loads the first 3 slides while you are seeing the loading screen. Once they are downloaded, you start watching the presentation. Presenter then begins to preload an additional slide every three seconds. This allows it to keep play without having to load the entire presentation. If you wan to limit the number of slides it is trying to preload (by default there is no limit), I can work on digging up the change you'll need to make to one of the XML files.
SWF content can be hard to work with due to the large number of variables of how it can play back. So, there is a separate function for preloading the SWF content. With only on SWF in your file, and the preloading option not making much difference, I suspect that that function is not the cause of or solution to the problem. I would start by asking how the SWF was created? It needs to be in AS3, as if it was made with AS2 it will likely fail to play back or have odd behaviour.