I was having this bizarre, intermittent Finder crash when control-clicking to bring up a contextual menu. It turns out that the StuffitCM was the problem.
Stuffit contextual menu plugins are known to cause problems like this. Go to /Library/Contextual Menu Items and move any Stuffit plugins to the desktop. If the problem is solved, trash the plugin. If you don't have any Stuffit plugins, experiment with the ones that are there.
And later on that page, I found a fixed plugin: