During playback, at least while using the Podcast Player app, the unit will spontaneously stop playback and switch to the screensaver (clock) shortly thereafter.  Sometimes the unit turns itself "off", meaning that the clock screen's background goes black.  When re-awakened, the unit should allow me to pick up the program where it left off, but it does not.  Instead, it starts from the beginning of the program.

Experiments imply that this is happening when the wireless network drops out.  If true, the unit should reconnect, rebuffer and pick up playback where it left off, instead of just stopping and leaving the user to figure out via trial and error where in the program the playback stopped.