Well, I wrote a c# program in an attempt to solve media engine inability (so far as I know) to resume mp3's after standby. What this does it is emulates an alt-f4 on the main window of media player, in the hopes that it gracefully shutsdown, and saves the mp3's location on standby. Then on resume it starts is back up again. It worked about 3 times out of 5 standby's for me, but something else in mediaengine is not behaving as expected. Sometimes it would start at the beggining of the song instead of resuming from the last location. But I guess this program could be useful in other ways so I'm posting it anyway.
usage mewrapper.exe "path to me.exe (or any other .exe)"
it'll start it by default, so you could use this .exe with a command line instead of the program, in this case media engine, to be closed and restarted between standby's...