Woah I have never heard of this before! Any chance you have another Chromecast somewhere in your house? Does it happen on that one too?
Is there any similarity between the files you're trying to stream - did you get them all from the same source, etc..?
(In tandem we are looking into what could be causing this - we definitely understand how horribly annoying would be)
Thanks for the quick reply.
In the process of investigating further, I had the same issue occur to me while not using Videostream. Thus, it appears that Videostream is not to blame. If I find a solution, I will post it here as a follow-up.