Almost sure a little bug. But you can make a rom backup and Titanium Backup of apps, do a fresh clean install and check if it's still present. If not, just reinstall your apps backup with Titanium
---------- Post added at 01:49 PM ---------- Previous post was at 01:48 PM ----------
The time I've used this ROM it was flawless. Give it a try my friend, I'm almost 100% sure lock screen still present after reboots.