Weird MP3 Conversion

I used Tunesify to convert a file from AIF format to MP3. The AIF file is a 36-second audio recording created with Griffin iTalk on my iPhone. The resulting MP3 file appears on my desktop as a 46-second recording, yet when I open it in Quicktime it shows as 39 seconds. When I play it, it stops at 36 seconds, and shows 2 seconds left. The good news is that the MP3 file sounds fine, but the inconsistencies in reported durations of the converted file make me hesitate to use Tunesify for other MP3 conversions. I wrote the dev about this a week ago, but havent heard back.

Update: I heard back from the developer, who was able to reproduce the eird result I encountered. It is apparently the result of Tunesify using variable bitrate encoding. The dev indicated that the next version of Tunesify will default to constant bitrate encoding to avoid discrepancies in the reported duration of converted files. If users want, they will be able to switch to variable bitrate encoding (but will apparently still get discrepancies in the reported times). I will update my rating once Ive tried the new version.

Drdul about Tunesify, v1.1