Some MKV videos start twice?

[Gary King]

I have a few big and high quality MKV videos. Some of them start "twice"; when I open them up in VLC, they will play for a split second (about 0.2 seconds), then start from the beginning again, essentially restarting once, and therefore starting at the beginning twice. This produces a "flashing" effect, since the first split second is played twice in quick succession.

Some more information: When it does this, I notice the filename in the title bar flash quickly when it restarts, and there is a loading bar that appears in the VLC "scrubber" for a brief moment, too. Also, this problem does NOT occur when I already have VLC running.

Why does it do this? Is there any way to fix this?

I'm using VLC 2.1.1 but I think this happened even before this version.