Screen capturing resulting in completely black or white image

[acidity]

I am trying to take screenshots of window by following methods described at:

http://guides.macrumors.com/Taking_Screenshots_in_Mac_OS_X

If I use the SHORTCUT method then all the resulting images are just black. Nothing but just black screen. If I use Grab, then the resulting images are only white.

What is the problem? I had taken screenshots using the SHORTCUT method and it used to work. Suddenly today its not working.

 

[Apemanblues]

Are you trying to capture a DVD screenshot? If it's a protected DVD then that's what you will get, unless you run it through VLC.

Otherwise, I don't know.

 

[acidity]

Nope.

Just plain windows to demonstrate some software. Very strange. Will research more tomorrow.

 

[acidity]

This gets even more strange. I was checking out this page:

http://silvermac.com/mac-os-x-keyboard-shortcuts/

If I use:

Cmd-Shift 4 = Select an area to be captured to a file

then I get a black image.

But if I use:

md-Shift 4, then press Space = Capture entire window

Then I get the correct output. The window is shown as it should be and not "black" or "white".

PS: I have recently downloaded QuickSilver and changed lot of keyboard mappings. Can that be an issue?

 

[wrldwzrd89]

This gets even more strange. I was checking out this page:

http://silvermac.com/mac-os-x-keyboard-shortcuts/

If I use:

Cmd-Shift 4 = Select an area to be captured to a file

then I get a black image.

But if I use:

md-Shift 4, then press Space = Capture entire window

Then I get the correct output. The window is shown as it should be and not "black" or "white".

PS: I have recently downloaded QuickSilver and changed lot of keyboard mappings. Can that be an issue?

If you have an application that blocks screenshots running, such as Apple's DVD Player, close it.

 

[acidity]

Closed all the applications (with just Safari running) and still the same result.

 

[Palladium]

It's happened to me!!

Suddenly I am getting exactly the same behaviour as the original poster. I have made wide use of selected screen shots (cmd + shift +4) in the past. Up to last week they worked fine. Suddenly today it gives totally black pictures. If I use Grab they are totally white. If I add spacebar to the above sequence I get a proper shot of the full screen but I only want shots of selected areas. Is anyone else finding this? Has anyone any fresh ideas? I am running a 2Ghz MacBook with 2GBytes RAM. DVD software is not running and I am unaware of anything I have changed since last week.

 

[Palladium]

All's well

I repaired privileges no change.
I did a full virus scan with ClamXav - no infected files.
Restarted the computer and bingo all is well. So I'm a happy bunny but I would like to know what went wrong.