When autobuild is enabled, M2M seems to do periodic rebuilds, even if you don’t change any files. This has 2 anoying side affects:
During a rebuild, a toolbar gets repeatedly added and removed if you have the target management perspective open. This means the the entire UI jumps about making it hard to see traces and shell outuput.
Even though nothing has changed, the dwl file still gets replaced. If you are downloading when this happens, the download fails, and you have to start again.