NWZ-S639F not playing whole tracks in SensMe

[quwells]

I use my '639 in the car, predominantly, using the SensMe channels.

I have a question about two apparent anomilies; possibly related.

1. When I turn the unit - wake it up - the track position for the (pre-selected) track is never at the beginning of the track unless the unit has been on 'hold' - in which case it appears to remember what track was playing when it was paused and held..

2. When listening to tracks, I find some of the tracks are truncated by a few seconds at the end. The few times when I have been able to skip back on a track - not always possible in the car - the track will then play its full length - not truncated.

I find this infuriating at times, and would like to understand why this is happening.

What can be done to prevent this happening?

Regards

Echo