WP-34S: Stopwatch - bug, feature, or user error?

[Marcel Samek]

I am running build 3575. When I start the stopwatch with CPX-R/S and then use it, everything behaves as expected. However, If I start the stopwatch and then just let it sit for a few minutes (4 to 5), the calculator looks as if it is still in stopwatch mode, but if you hit R/S to start the timer, it flashes something on the screen and immediately exits the stopwatch.