Can you do me a favor and test your alarm clock?
Set it for about 5 minutes out and allow the screen to go to sleep...
I did this along time ago with a sense rom on my HD2 and it didnt play nice with the alarm clock...I was quite furious when my alarm went off in the morning and there was no way to turn it off or snooze it. I ended up having to pull the battery...From the forum post at the time, it seemed that a lot of people deleting this file were encountering similar issues.
As an alternative...I am using Widget locker to acheive the stock sliders on the lock screen and it works flawless.
Google Nexus One (ROM: MIUI 1.6.10)
LG G2X (ROM: Stock Rooted)
Samsung Galaxy S 4G (ROM: Stock Rooted)
HTC HD7 (ROM: Stock)
T-Mobile US HTC HD2 (ROM: MIUI)
MyTouch 4G White (ROM: Stock)
MyTouch 4G Black (ROM: Fusion 1.1.6)
T-Mobile Vibrant (ROM: Bionix 1.3.1)
B&N Nook Color (ROM: Phiremod 6.3)
HTC Sensation 4G (still waiting for UPS)
...plus a whole closet full of older phones