Different track length after converting to ogg Options

[Pete7874]

Sometimes when I convert from another lossy format such as MP3 to ogg, the resulting track length is different. For example, I converted a 256 kbps CBR MP3 with a duration of 1h 59m 47s to q2 OGG using aoTuV [20110424]. The resulting ogg file has a duration of 1h 59m 39s. Where did the 8 seconds disappear?

I realize it is not a huge difference. I was just curious what causes such things to happen?

Thanks!