Not sure what causes this, but when ever I do anything too alter an image, moving an image, smuding etc, it does this. Anyone know how to prevent this?
Perhaps your computer can't handle all those programs at the same time. Could be some sort of lagging?
Try changing the brushes to default, you might have it on scatter. You can change any brush to scatter. Ex: eraser, smudge, or uhm, a brush. Just open the brush panel and click the little right arrow in the top right of the menu and click load defaults.
Ya i think it has something to do with ur computer you probably need some more ram or a new processor
If you look at the layers palette, are the random bits of jumbled car showing in the layers thumbnails? If so, it's an internal photoshop issue, most likely an incorrect setting, if not, it's more likely lag causing extreme crazy artifacting. Check the image resolution. If it's the native res of a full resolution set 10mp camera, it could be huge, causing image processing to take an age, if its not very big, check your system performance panel in the Task Manager. Check that nothing is draining your system resources. If theres anything in there using a ridiculous amount, end the process (unless you don't know what it is, then be careful). It could be a virus sucking up your gigahertz.