if you jog through a media file while its peaks are being built, the peak-building stops and begins from the beginning. once the peaks are complete, you can click through the file, but until then, peaks will be reset at every click.
this bites me a lot as i flip through bulk catalogs/libraries of longer samples. i don't always want to wait for the peaks to be built before surfing the audio file, getting an aural sense of what's going on.