Ive had no troubles with .avi files but Im having problems with .mp4 files. This is my log:

24/05/2006 2:11:57 PM info ********** Report session closed ***********
24/05/2006 2:11:54 PM warning Converting this file may cause poor result (audio glitches or out of sync).
24/05/2006 2:11:54 PM warning File "xxxxxxxxxxx.mp4" has a container format (QuickTime/MPEG4 format) that is partially supported now.
24/05/2006 2:11:47 PM info User default language : 3081 (0x0C09h) - English (Australian)
24/05/2006 2:11:47 PM info System default language : 3081 (0x0C09h) - English (Australian)
24/05/2006 2:11:47 PM info Version 2.0.12.126
24/05/2006 2:11:47 PM info ExeName : "C:\Program Files\ConvertXtoDVD\ConvertXtoDvd.exe"
24/05/2006 2:11:47 PM info OS : Microsoft Windows XP Personal Service Pack 2 (Build 2600)
24/05/2006 2:11:45 PM info ******************** Report session started ********************



What is the problem? How can I overcome it?

Cheers

Simply using different format.
mp4 is container like avi, there are numerous of different formats using this and all are not fully supported.