Video skips backwards and loops

[scar_tissue]

Hi, im new to using VLC media player so my apologies if there is a blindingly obvious solution but im having problems when i try to play MKV files. When i click play it seems to be fine however once it gets to a certain point the video simply starts again from the beginning, if it try starting the video from a later point it plays (though not from the point that i tell it to just from a latter point) but after a while it will skip backwards and start playing from an earlier point and if left to itself just go in a loop again and again. When i go in message the only error message that seems to occur every time it skips back is "end of video preroll", please help.

The message:
mkv debug: seek got 0 (0%)
mkv debug: seek got 0 (0%)
mkv debug: seek got 0 (0%)
main warning: buffer is 98500 late, triggering upsampling
main debug: End of video preroll
main warning: late picture skipped (98504379999)
qt4 debug: Updating the stream status: 4
qt4 debug: New Event: type 1103
qt4 debug: Updating the stream status: 4
main debug: control type=1
libass debug: Resetting libass track after time discontinuity

[blueyedsoul]

Sorry to necro this thread, but I'm having the same issue. Does anyone know the cause or a solution for this?