Confirmed that this issue exists.
Target: Â iRiver iHP-140
Build: Â 6-6-07 bleeding edge (about 6 p.m. California time)
Switch car mode on, connect the player to power, and start playback. Â Either disconnect the power cord from the player or turn the power off. Â A press of play will start the player again. Â However, reconnecting the power cord instead to the player or turning the power on again, after 2, 5, 10 or 15 seconds, and the player freezes in 2-5 seconds and needs to be restarted with the reset button (and sometimes will boot into iRiver at that point).
Being reported on Flyspray.