If you want a lockscreen to work properly, it's a bit tricky:
go to settings > phiremod settings > tablet tweaks > Uncheck 'Disable Lockscreen'
When it turns back on, you should be greeted by a sliding lockscreen. There are 3 others you can try, and they're in Settings > Phiremod Settings > Lockscreen > Lockscreen Style (IIRC on the last title)
recommended setting changes:
go to the homescreen, and press the button with 3 lines that's on the status bar, and tap Preferences. Go to Homescreen Settings. Set 'Number of Columns' to 8 and 'Number of Rows' to 10.
Menu Button > Preferences > Behavior Settings > Uncheck 'Enable Auto-rotation' (it causes lag and other problems when enabled), Home key action to Open/Cloce app drawer, check Home key to default screen (if unchecked)
Settings > Phiremod Settings > Performance >Tap OK > CPU settings > set Available Governors to 'interactive', Min CPU Frequency to 300, Max CPU Frequency to 1200 or 1300. It will need to be set each time you turn on your Nook, unless you check the 'Set on Boot' checkbox.
Go to homescreen
Menu Button > Preferences > Advanced Settings > set both 'Drawer Columns' settings to the highest, turn on '3D Drawer' if you like Eye Candy, Opening Speed to 0, for cool effect.