Hello to you all.
Just here to say that I've been having the same issue for months, and I can't find a solution anywhere.
Apple doesn't seem to take a look at this topic either.
About some characteristics of the issue:
-It is NOT only with Finder. It is with ANY drag and drop situation.
-Restarting Finder do NOT fix the issue neither deleting Finder preferences. Only rebooting fixes it. Temporarily.
-When trying to drag an item it gets stuck on the cursor for a few seconds, and if you won't constantly type "esc" or right click on something it can get stuck for a long period of time.
-It happens on Mavericks and Yosemite. So an update won't work for this issue.
Hope anyone up there could start working on this. It is really annoying and unproductive. 😐