I'm not having any trouble with 700k videos (which are not h.264).
All of the h.264 videos, on the other hand, require much extra care to play or transcode. The problem is that the way
GetFLV is building the flv file from the stream is a little bit of a kludge in regard to the way it is time-coded. You may notice that h.264 downloads go past 100%. This is related to this issue.
However,
EffectMatrix Total Video Player plays them back pretty well. And - believe it or not - the files actually play even better once transcoded to another format like xvid.
The best transcoder for the files produced by
GetFLV is
Format Factory. You just need to be careful to set the framerate to that of the original flv file.
So, my suggestion is to try
EffectMatrix Total Video Player to play the file, or try to transcode it to xvid with
Format Factory.
If none of these work, provide the link/title to program you're having trouble with.