Can't Capture Video In Vegas Pro 11 or 12

I just discovered this problem today and have never had this happen before. When I click on the capture video command in Vegas Pro 11 it opens the capture window but then gives me this error message:

"The device 'corelscreencapture' could not be opened. Please make sure it is turned on and not being used by another application or user."

When I click on 'Video' at the top of the capture window it lists:
Corel Camera Plug-in
Corelscreencapture
UScreenCapture

The capture window has the title - Sony Video Capture 6.0 - default*
In the preferences the external video capture application is set to - C:Program FilesSonyVegas Pro 11.0vidcap60.exe (the back slashes don't show in this text format).

I did have Corel Video Studio Pro 5 installed so I uninstalled it and used Ccleaner to remove further references to it. I also installed Vegas Pro 12 trial version but I still get that same error message in both Vegas 11 & 12. When I go directly to the vidcap60.exe file in Vegas 11 & 12 and click on it it gives the same error message. Please help if you can as I am unable to capture a much needed video from a tape in my old Sony Hi8 video camera.

Intel 2.67GHz Core2 Quad CPU.
8 GB RAM
NVIDIA GForce GTX 570 superclocked
Windows 7 64bit

Thanks, John. I am using firewire and your words stirred me to check the firewire cable connection to my desktop. It had backed out just enough to lose the connection so I pushed it in and all is well. Just didn't expect that to be the problem since it's never backed out before. The simple solutions are always the best ones.

Intel 2.67GHz Core2 Quad CPU.
8 GB RAM
NVIDIA GForce GTX 570 superclocked
Windows 7 64bit