background transcode don t work

hi

trying to transcode clips, and or sequence..but when i use the run in background option it doesn t work

it suddendly finish, i can see the list of the clips created with the extension .new..buty there is nothing

and of course it is too quick..just 1 second and it finish all

i can see the 3 background services seems that are regularly running..so what can be the problem?

thanks