I just upgraded from 2.4.0.0 to 2.4.1.0 today and found this apparent bug...
The Preview layer break operation doesn't work right in 2.4.1.0. I like to use the single left wedge control (<) to scroll a little before the layer break, then play from there, to judge how good that choice of layer break will be. But that doesn't work right in 2.4.1.0. The "<" control freezes (stops) at the LB and will not scroll to a prior point in the video! The double left wedge control (<<) scrolls to a point before the layer break, but then the playback is apparently incorrect. It looks like some playback glitches, things are left out or introduced, or something is very wrong here!
I tried this on two different long movies (7G+) intended for burning to a DL disc, same thing. Then I reverted to 2.4.0.0, and everything is OK again with the Preview layer break feature.
I burned one of those movies with 2.4.1.0 and it verified OK. I haven't tried to play it yet to check how the the layer break works. However the resulting disc scanned reasonably OK with Nero CD-DVD Speed.
I'm running Windows XP SP2, and used a Lite-On DH20A4P 9P59 for the above observations.