playback problem

When the sound icon is selected the playback doesn’t work correctly; it plays only the sountrack but not the video (it shows only the image of the selected panel; the timeline bar is stopped on that frame while the soundrack continues correctly). if I click the sound button off, the animation plays correctly (but there’s not the sound).
How can i play my animation with sound to work optimally on timing (not after exportation but in playback)?

Thanks ahead.

Hi, Paikelts,
Please contact
Without seeing the real scene, it’s hard to tell what caused it.