Relates to Sequencer and Renderer
Blender 2.61

Windows Vista SP2

If a portion of an video with audio clip is cut, deinterlaced, and then rendered, the audio will become incorrect, as if the data block shifts.

1. Open a video strip with audio.
2. Cut a segment from the middle of the audio and video strip.
3. Select the video strip and check "deinterlace" in the properties panel.
4. Click play in the timeline and the correct audio should play with your cut clip.
5. NOW, go to the rendering panel, select h.264 video with mp2 audio.
6. Render clip and listen to the audio. It should be different from what you heard in step 4.
7. Go back to the timeline and click play and you will notice the audio segment is different.