The 10.8.2 version of "helpd" incorrectly sets "PreventUserIdleDisplaySleep"

Question

Ever since upgrading from 10.8.1 to 10.8.2, I have noticed that after a short amount of time of using my machine, the system stops going into "display sleep" when idle, and it never again automatically activates the screen saver.
After investigating, I noticed that the "helpd" process is incorrectly setting "PreventUserIdleDisplaySleep". This is illustrated by the following output of "pmset -g assertions" ...
% pmset -g assertions   
10/7/12 11:51:47 AM EDT 
Assertion status system-wide:
  PreventUserIdleDisplaySleep  1
  CPUBoundAssertion            0
  PreventSystemSleep           0
  PreventUserIdleSystemSleep   0
  ExternalMedia                0
  UserIsActive                 0
  ApplePushServiceTask         0
  BackgroundTask               1
Listed by owning process:
  pid 18(powerd): [0x00000005000001d7] 11:24:18 PreventUserIdleDisplaySleep named: "com.apple.powermanagement.delayDisplayOff"
  pid 12873(helpd): [0x0000000c000002a1] 00:10:34 BackgroundTask named: "com.apple.helpd.sdmbuilding"
... etc. ...
I see no valid reason for a background process like "helpd" to prevent the screen from going to sleep ... especially a long-running background process. I therefore believe that this is a bug. My guess is that the Apple developer might have accidentally typed "PreventUserIdleDisplaySleep" instead of "PreventUserIdleSystemSleep" in the 10.8.2 "helpd" source code.
I will soon report this to Apple as a bug. In the mean time, do any of you have thoughts about this issue?
Thanks in advance.

Answer 1

I realize now that helpd is not the cause, but rather, certain other programs are setting the PreventUserIdleDisplaySleep power-management assertion within powerd, and that this assertion remains in effect even after those badly behaved programs exit. I'm looking for a way to clear PreventUserIdleDisplaySleep within powerd without killing and restarting powerd.
Does anyone know how to do this?