this is the video URL [which I inserted into "Open network stream..."]:
http://www.youtube.com/user/LuisaElea#p/u/5/QlX0UlLmakc
[and many others. however, some work fine.]
download also fails. thank's for help.
aver
qt4 warning: Input option: http-caching=1200
ts warning: TS module discarded (lost sync)
ps warning: this does not look like an MPEG PS stream, continuing anyway
ps warning: garbage at input, trying to resync...