When using Structured Interval Training, after rest time and going to next lap, for the last 5 second, it go to other display that show up the sound DI DI DI DI DI for 5 times only, it is important that to have the time "second", 5 4 3 2 1, for the last 5 second to show up in watch instead of just the DI sound only! Also during this moment, display should active, but it will timeout. Hope this can be fixed... Even my previous 645 does not have this issue.