AC3 disappears when file changes

While playing movie that deals with two files, added on playlist,AC3 CD 1 and AC3 CD 2 for example. When the first file is played using digital out AC3 sound, everything is alright, but when the second file, CD 2, starts playing, AC3 disappears and the sound is plain 48 khz.
AC3 returns when I open the file again manually. Bit anoying while watching the movie..

Is by the way normal when listening with spdiff enabled the signal is only send to digi out(when file contains AC3)? When the file doesn't contain AC3, sound comes out from every output. (front, rear, coax 48khz).

I would appreciate help, thank You.

[Levis]

Doesn't any one know what's wrong? Version is 085.488, because newer versions crash if you try to open preferences!!