Hi. Have found that speed change effect applied to a clip is not retained when moving the clip in the time line. Not sure if it only happens when that clip is moved together with other clips selected also.
On my system, it seems that if the file name has no spaces or special characters in it, it may work. In my case by changing the clip from: "Screencast 2017-05-23 00:36:22.mp4" to simply "cast.mp4" This allowed the speed effect to work. Not sure if this is entirely related, but it's repeatable on my system.
for me the speed effect often gets truncated when closing and opening the session again.
when i apply speed effect usually time line get dark, or the clip speed don't correspond what is suppose to be done. :/ ...i also try to ungroup, audio and video...but no way! if anyone know what can i do...i appreciate it.
Since then I moved to another more powerful machine also with UbuntuStudio 18.04 Seems to have sorted out the problem. So whether it was just the hardware flaking out or some other hardware / software issue, I couldn't say. But I suspect it may have been tied to processing power. Interesting Ben about the file names. I almost always used file names without spaces using hyphens or underscores instead and no other symbols. But most file names were long. Can't try this out on the old system at the moment. Hope this helps.
A lot changed since this report and the speed effect got a rewrite so I marking this as resolved.