I'd be curious spectral as to whether or not it just may
be the difference in a setting somewhere within VLC itself? The basic settings
of VLC are just that---pretty basic. But have you clicked around to see the more "advanced" settings? (Ergo "MPlayer" and "Xine", especially the latter where it has "Master of The Known Universe"?) These "advanced" settings would require a rocket scientist to figure out half the time with a doctorate in spatial physics!
Most of these in the advanced settings have such a section dealing with "immediate play" or "play from cache". They may not be worded exactly like that but similar enough that you'll know it when seen. I know Xine does seems so from all the times I've set that up.
That's about all I can offer for advice at the moment. Sorry it's not more.
I hope it helps though.