Selected text not highlighted

When selecting text, I drag normally across the word/s and this is shown as selected by being highlighted. Then I can perform operations such as cut, copy, paste etc on the selection.

When using Safari today I find that the selected text isn't highlighted giving, wrongly, the impression it isn't selected. But copy, cut, paste etc work as normal. I then found that this problem was not confined to Safari but was the same in Word, Pages, Excel and even the Finder.

I opened the Mouse control panel and as I did the selected text became highlighted. But bringing the application to the front instead of the control panel made the highlighting disappear!! This could be repeated. Control panel as front window highlight visible in Safari behind frontmost window, application (Safari) at front highlight not visible. See https://dl.dropboxusercontent.com/u/4198612/PreviewScreenShot002.png

• Tried several restarts but it didn't the solve problem.
• Tried resetting PRAM but it didn't solve problem.

Even in typing this message the highlighting doesn't appear visible. To add bullets above I selected the two line (no highlights) and presses the bullet button.

Anyone else experiencing the same problem? Anyone got a fix?

Regards

David Barr

I' using OS X 10.8.4 (12E55) on an iMac with 8 GB 1333 MHz DDR3 of memory.