Avi to Mp4 help

Hey guys, recently i have been wanting to convert video .Avi files to .Mp4. Im using Ipod video converter but the problem is that if the movie files are over 30-45 minutes long the audio goes out of sync with the video. The first part will be fine but as soon as it hits the 35-40 mins mark its out of sync.

Does anyone know if its the software im using or my computer? Or are files this length not supposed to be converted:). Or is there simply another program that can sync them together again? Any help would be much appreciated!

Due to ipods being erm...a bit on the slow side shall we say with syncing they will allways go out from about 15 minutes long in my opinion and experience. Ive used this before http://www.download.com/Ultra-Video-To-iPod-Converter/3000-2194_4-10532474.html?tag=lst-7

Hope it helps free to :D

i'm not sure if this helps or if u can even do this w/ ur software but u might try adding more keyframes

Ive had a better look at it and keyframes has come up a bit actually. Have a look at this and test it out
http://www.ipod4video.com/solvingvideo.html

Also these guides have some useful info
http://forums.afterdawn.com/thread_view.cfm/385738

Hope this is more help