I stopped using Imesh about 6 months ago due to it never connecting, but even when I did use it I never used the media player that came with it.
You are probably better IMO using an external media player, my favourite one is one called ZOOM player which comes with a HUGE collection of codecs. Its very rare I can't get a file to play on it.
Do a search on google for zoom player ace codecs and see what you think.