Very strange built-in iSight behavior

Question

I'm seeing some strangeness with the built-in iSight camera on my early-2008 15 inch Macbook Pro.  At some point I noticed that the iSight would simply stop working.  A PRAM reset would enable it again but then it would stop working for no apparent reason.  Here's where things get interesting.  I did a PRAM reset and logged in and the iSight worked.  I plugged in a USB hub (with three external drives, a smart pen dock, a Snowball microphone and a Bamboo Fun tablet plugged in) and it worked until I rebooted with the USB plugged in.  So I decided to try simply rebooting without the hub plugged in and not plugging it in until after I had logged in and gotten to the desktop.  As long as I did that the iSight camera continued to function. 
I came into the office today, my first day back after realizing what I thought was going on and booted the machine.  Now at work I have an Apple USB keyboard.  I deliberately didn't plug it in until after I had logged in however, I logged out for a moment and then logged back in with the USB keyboard still plugged in.  The iSight was disabled.
So here's my conclusion and my question.  It appears that the system profiler 'loses' the iSight camera on the USB bus if any USB device is plugged in at any point before logging in to the desktop.  Has anyone seen anything like this?  I had initially thought it was some kind of strange hardware issue, perhaps a loose connector but then realized it can't be that because if it were a PRAM reset wouldn't resolve it.  So it must be something with the system profiler.
Question 1:  Is the system profiler something on the firmware or is it software. If the latter is there any safe (or reasonably safe) way to get at it?
Question 2:  Is anyone aware of some weirdness with the early-2008 vintage Macbook Pros and the built-in USB ports?  (I have verified that it does not matter which USB port I use.)
Question 3:  If anyone has seen this, were you able to fix it permanently?  If so, how?
Thanks in advance

Answer 1

When your iSight next stops working, consider Apple's http://support.apple.com/kb/HT2090 suggestions.
The PMU (SMC) "reset" suggested there often restores normal function.
Instead of PRAM, the recommended fix for your problems
is a PMU/SMC reset: http://support.apple.com/kb/HT3964.
If your problems continue after trying all of Apple's relevant "Troubleshooting" suggestions, before going to work on your System Profiler (System Information in Lion) or preferences, use your Mac's Disk Utility to repair permissions and then download and apply the latest Combo Update.  For your Mac OS, the current Combo is at http://support.apple.com/kb/DL1484.
Repair permissions again immediately following the system restart that completes the Combo update.
Properly applying the Combo version of updates can sometimes correct software problems, and it costs nothing but a few minutes of your time.
However, repetetive symptoms may be an indication of an intermittent hardware problem.
If your trouble is being caused by a hardware problem, there are no user serviceable parts of your Mac's inbuilt camera.  Therefore, if your problem continues to be only temporarily corrected, when the problem becomes too annoying, ask your Apple-Authorized Service Provider to check out your symptoms to determine whether your Mac needs service.
Message was edited by: EZ Jim
Mac OSX 10.7.3