I have divx file which contains 3 episodes of OFAH. I want to split them in 3 parts. I read manual on https://www.videohelp.com/virtualdubedit.htm and started working (because of "VBR audio stream detected" I downloaded Virtualdub MP3 Freeze)

And problem...

begining of second episode is between keyframes (that first "keyframe to keyframe" length is 8sec!) so i cuted that 8sec with Full Procesing mode re-edited (deleted part that i don't need) and compressed with Fast recompres and same codec (mpeg4) as orginal file

After that i cuted from end of that "8sec " to the end of that second episode.

Now I started to join re-edited 8sec with the rest of the episode. I used Appen function and finished.
Video, i meane picture is OK!
But sound... on the plase where i joined files is 1sec sound "UUIIIP", I am sure that virtualdub inserted that sound.

What sems to be a problem?