Problem with Playing audio streams in BsPlayer

[SuperNick]

Sometimes when I watch some films with bsp I can’t choose alternative integrated audio streams. The film and its default audio stream are played well by bsp, but when I enter BS Player’s menu (trying to change the stream, Audio -> Audio Streams) I can’t select any stream, the icon is inactive…
It happens when a film has an integrated audio stream, but some films and their audio streams are correctly played by bsp.

However this film (I mean the film whose integrated audio streams bsp doesn’t “see”) and any of its integrated audio streams can be easily played in Nero Show time player.

Help me please. What should I do to solve this problem and to enjoy watching such films with BS Player?

ps: I use BsPlayer_pro_ver. 2.26; K-lite mega codec pack 375; Windows XP_SP2+all updates; CPU - P4 3 Ghz; 768 Ram; GeForce 4.