A friend of mine has asked me to post an issue he's having with his DCS, since I'm online and he isn't. I know nothing about DCS (I'm a conventional and sometimes TMCC guy.) so hopefully I've understood his issue enough to convey it here. Forgive me if I use the wrong terms and such.
For a while he was having signal issues, but tracked that down to a shorted wire. Once fixed he was getting 10s all around. So he decided to upgrade his TIUs and handheld to 4.30 from 4.10 that he had been running. He has 2 TIUs, and runs in super mode. What he found was that when the locomotive went from a TIU-1 controlled block to TIU-2 block and he wanted to lower the smoke output, the only thing it would do is turn smoke off no matter what smoke level you select. The lights (headlight, marker, ditch, and cab) would also go off, and not come back on. He thought he had signal problems again and spent 4 days trying to figure out where the issue was, but on a whim he downgraded back to 4.10 since he had 10s when last he ran it and everything has gone back to working.
So don't know if this is a software bug, or something else someone has come across, but we don't know what to do to fix this so things work with the newest software.