I've noticed this bug long ago but I thought "It will be fixed soon" all the time, and it's still there...
Here's what happens: When mixmapping etc is enabled and you copy and paste parts of the track, all the blocks that need connections (eg roads) will lose the connection. That's not a big drama, because you can always undo and disable the functions to do it properly, but it's still unsettling.
However, there's a bigger problem with the inflatable block in Stadium. I used the copypaste tool and made before and after screenshots. http://puu.sh/gZv9G/ab0b8437f9.jpg -> http://puu.sh/gZvgM/a872d6ee7d.jpg. And the actual problem with that is, the game crashes when you do anything that involves that bugged block behind the road pieces. This should have been fixed by now, because it's been around since the integration of mixmapping!
I had to rebuild quite a few maps because of it
-gado
btw, If this is the wrong forum I'm sorry. It's 3am and I'm tired
