Hmm interesting otto... I'll wait till the video is done loading before I fully look into it, but I think I already have somewhat of an idea.. theres so much stress on the brace that it pops right of anything it's attached to? If not that... then I'm really quite intrigued.
Okay, now the video is loaded.. I can't actually tell what is going on in the video... When possible I try not to have to load up the machine due to spending my time wisely... but in this case I may have to
Hmm alright... so I can't quite replicate it as often as you seem to be... So I can't figure too much out with. However...it seems as though the block isn't really connected to anything... This is due to when you line two blocks up again each other, they don't actually connect. So the only places where it seems to be connecting, is the suspension, and the braces which appear to be connected to the other set of blocks...
So whats happened here, is that in trying to connect the braces to those blocks, sometimes they stay connected, and sometimes they jump to the other block, thus leaving it to fall (this only occurs if BOTH braces jump and attach to the other blocks)
Does this sound consistent with what you believe is happening/seeing?
The blocks between the wheels that are falling are connected with braces to the blocks right above.
I could have just made the blocks differently so they connect to other blocks without having to use braces, and I will do so later, but I found this bug report-worthy xD
I can't say for sure if (the lower end of) the braces jump to the other blocks or that they just don't attach to anything at all.
Those other blocks will stay up however, as they are part of the frame.
And one more thing, this only started to happen when I had a lot of blocks and braces in this build.
So if somebody is trying to recreate this bug, over using wood and braces might be the way to go.
Hmm... alright, all very interesting to note. Cheers for the bug I'll throw it up onto the compilation thread... Down as... Braces when stuck between blocks, jump to other block at random with large builds...