You could be creating a lot of conflicts and initializing of commands that are interfering with each other and possibly canceling each other out which can create erratic performance. Try paring things down to just the basics that may be required for your device (such as the [rawdisplay] and [folders] sections).
You could even try starting with no sys.txt at all and see what happens. As an example, here is my complete sys.txt...and everything works, but even it has a bit of bloat, but I really have not bothered to mess with it too much.:
Spoiler: See Text