Erratic iSight problem on MacBook Pro

Question

The iSight camera on my MacBook Pro 17" comes and goes constantly. It vanishes from System Profiler at times too. I've rest the NVRAM and logged in as other users too. Its like it has a mind of its own. Turning on the green LED and off, then refusing to let other programs like iChat or Photo Booth from connecting, sometimes saying the camera is in use even. Its very fustrating also since I use the camera sometimes in iChat or Skype only to have the image lockup. The camera vanishes. I'm not sure if its a hardware problem or a kernel problem.
I've decided to try to monitor its failure with the HardwareGrowler.app. The camera randomly connects and disconnects. Growl notification show:
USB Disconnection
Built-in iSight
USB Disconnection
IOUSBVendorSpecifiDevice
USB Connection
IOUSBVendorSpecifiDevice
USB Connection
Built-in iSight
*Bellow is an example of what I see in my logs*
Sep 18 17:13:39 yazz-mac kernel[0]: USBF: 408.650 [0x4723a00] The IOUSBFamily is having trouble enumerating a USB device that has been plugged in. It will keep retrying. (Port 4 of hub @ location: 0xfd000000)
Sep 18 17:13:39 yazz-mac kernel[0]: USBF: 409.376 [0x4723a00] The IOUSBFamily has successfully enumerated the device.
Sep 18 17:13:58 yazz-mac kernel[0]: USBF: 427.990 [0x4723a00] The IOUSBFamily is having trouble enumerating a USB device that has been plugged in. It will keep retrying. (Port 4 of hub @ location: 0xfd000000)
Sep 18 17:14:02 yazz-mac kernel[0]: USBF: 432.160 [0x4723a00] The IOUSBFamily is having trouble enumerating a USB device that has been plugged in. It will keep retrying. (Port 4 of hub @ location: 0xfd000000)
Sep 18 17:14:05 yazz-mac kernel[0]: USBF: 434.990 [0x4723a00] The IOUSBFamily was not able to enumerate a device.
Sep 18 17:14:06 yazz-mac kernel[0]: USBF: 435.809 [0x4723a00] The IOUSBFamily is having trouble enumerating a USB device that has been plugged in. It will keep retrying. (Port 4 of hub @ location: 0xfd000000)
Sep 18 17:14:11 yazz-mac kernel[0]: USBF: 441.327 [0x4723a00] The IOUSBFamily is having trouble enumerating a USB device that has been plugged in. It will keep retrying. (Port 4 of hub @ location: 0xfd000000)
Sep 18 17:14:12 yazz-mac kernel[0]: USBF: 442. 53 [0x4723a00] The IOUSBFamily has successfully enumerated the device.
*Some info about my MacBook Pro*
Model: MacBookPro1,2, BootROM MBP12.0061.B03, 2 processors, Intel Core Duo, 2.16 GHz, 2 GB
Graphics: ATI Radeon X1600, ATY,RadeonX1600, PCIe, 256 MB
Memory Module: BANK 0/DIMM0, 1 GB, DDR2 SDRAM, 667 MHz
Memory Module: BANK 1/DIMM1, 1 GB, DDR2 SDRAM, 667 MHz
AirPort: spairportwireless_card_type_airportextreme (0x168C, 0x86), 1.1.9.3
Bluetooth: Version 1.9.0f8, 2 service, 1 devices, 1 incoming serial ports
Network Service: AirPort, AirPort, en1
Network Service: Parallels Host-Guest, Ethernet, en2
Network Service: Parallels NAT, Ethernet, en3
Serial ATA Device: ST9120821AS, 111.79 GB
Parallel ATA Device: MATSHITADVD-R UJ-846
USB Device: Built-in iSight, Micron, Up to 480 Mb/sec, 500 mA
USB Device: Apple Internal Keyboard / Trackpad, Apple Computer, Up to 12 Mb/sec, 500 mA
USB Device: Bluetooth USB Host Controller, Apple, Inc., Up to 12 Mb/sec, 500 mA
USB Device: IR Receiver, Apple Computer, Inc., Up to 12 Mb/sec, 500 mA
*Some info from System Profiler when the camera appears to behave correctly*
USB High-Speed Bus:
Host Controller Location: Built In USB
Host Controller Driver: AppleUSBEHCI
PCI Device ID: 0x27cc
PCI Revision ID: 0x0002
PCI Vendor ID: 0x8086
Bus Number: 0xfd
Built-in iSight:
Version: 1.84
Bus Power (mA): 500
Speed: Up to 480 Mb/sec
Manufacturer: Micron
Product ID: 0x8501
Vendor ID: 0x05ac (Apple Computer, Inc.)
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Answer 1

Hello Aaton
If you have not installed any new hardware since your MacBook Pro worked correctly, it is possible that your problem may be hardware related.  Because of the intermittent nature of your problem, unless the problem is repeatable when running some particular software or performing some function that could indicate possible software or device conflicts, hardware problems in your Mac seems even more likely.
Unless you get better suggestions from iNtel Mac users, here are the common solutions that help most avoid a visit to their Apple Service Technician for the "in use..." or "no camera connected" errors. You have already tried some of them, but I leave the entire list for possible use by other readers.
None of the suggestions is complicated, but the only way to find which one will work for you is to try them one-by-one until you find the one that fixes your Mac.
(0) Disconnect any unnecessary peripherals while you do your testing to rule out possible conflicts. 
(1) Restart your Mac. Sometimes that is all that is required.
(2) If you use VMware Fusion to run Windows on your Mac, consider disconnecting iSight from your Virtual Machine as recommended by user "The.VCI" in this post.
(3) If you use an HP printer/scanner with your Mac, consider the "daemon" suggestions from user "parkersal" in this post.
(4) Check for any running applications, Login Items, or widgets that can use your iSight. (It is easy to forget widgets like Mirror in your Dashboard.) As explained in Apple's iSight "Your camera is in use by another application" message, iSight can be used by one application at a time.
(5) Try every suggestion re: Built-in iSight in How to Troubleshoot iSight. Be sure to include the checks for whether the problem is "application-specific" and "user-specific".
Click here if you need help creating a new user account to check whether your problem is "user-specific" during Troubleshooting.
(6) If resetting or the other troubleshooting suggestions do correct your problem, try the following:
• Backup your Home Folder, or at very least, your important files.
• Repair permissions. (Click here if you need help.)
• Then download and apply the Mac OS X 10.4.10 Combo Update v1.1 (iNtel).
• Finish with another Permissions Repair, and then check your iSight again.
Users have reported fixes to a variety of audio, video, connectivity, and software conflicts and unreliability issues after properly applying Combo Updates.
(7) Some iNtel Mac laptop users have also reported success after unplugging their Macs and leaving the battery out for half-an-hour to overnight.
(8) If none of these suggestions work, contact your retailer, Apple, or your Apple-Authorized Service Provider for professional help.
EZ Jim
PowerBook 1.67 GHz   Mac OS X (10.4.10)    G5 DP 1.8  External iSight