Missing speech in campaign

[poderoso]

Hello all,

After flying several missions in the SP campaign, I noticed some errors in my console. Apparently my game cannot find the speech files for the campaign story. What happens is that the text is shown on the screen, but there's no sound.

For example, on the screen I see:
"Let's get this over with quickly. I don't want any heroics, understand?"
and then the console shows:
"[2167] ERROR [SOUND] Sample $bob/speech/gb/Actor1/Let_s_get_this_over_with_quickly_I_don_t_want_any_ heroics_un.wav not found"

Under the bob folder there is no speech folder, so at first I thought there was something wrong with my installation, but after installing it on win XP the folder was still empty.

Has anyone seen this problem, too?