Stuttering when cutting

I have two videos - one in each track. The video in the upper track is cut so for some seconds it reveals the lower one. No transitions is used. However, when revealing the lower layer it stutters. Adding a very short (3- frames) fade transition prevents the stutter. If I hide/mute the upper track it also does not stutter. This happens in the timeline as well in the rendered result.

Edit:
I made a short demonstration of the problem here: http://youtu.be/8Fz98KjndH0

Ubuntu 12.04 (beta 2)
Kdenlive Version 0.8.2.1 Using KDE Development Platform 4.8.1 (4.8.1)

I tried with the git version from ppa as well. Same result.

BUMP :-)

Also happens with Ubuntu 12.04 and Kdenlive 0.9.2

Hi, have you rendered out the section of video that has the error and stepped through that outside of kdenlive to see if the glitch is transferred to the final output and have you tried editing with proxies. Just to see if it's an editing playback issue or seeking / decompressing issue with the codec and formats you're using.

What was the original source format. Could the problem lie in the transcode or remuxing from original source to mkv?