I'd hate to resort to rooting just to solve the problem.
I checked out a couple of the Clipboard managers in the Play Store and interestingly enough, one of them said that if you were experiencing crashes during copy/paste on a Samsung Galaxy S III then you should contact Samsung support. Anyway, you might consider trying a 3rd party application (ClipIT:
http://market.android.com/details?id=com.smartandroidapps.clipper or
Clipper:
http://market.android.com/details?id=org.rojekti.clipper) to manage your clipboard and see what happens.
Finally, I'd be interested to know what happens if you merely long-press in an empty text field. Do you get the Paste/Clipboard option that's normally shown?
http://img.tapatalk.com/d/12/09/11/a3eryge5.jpg If so, you could select the Clipboard option and manually delete all of the items from the Clipboard.
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