I have Clipboard Merging turned on and am running into erratic/unpredictable behavior. Many times when selecting text, typing cmd-c, selecting additional text, typing cmd-c-c, produces merged content from the previous-previous copied text and the current selection. For example, say I've been working in Xcode and have done a bit of copy-paste coding (I know, I know) and then switch to Safari to copy an issue number and want to append the description for pasting into the commit. I select the issue number and type cmd-c (the Edit menu briefly highlights) then select the description and type cmd-c-c (receiving the notification sound), go to paste and end up with the description appended to the last item I had copied in Xcode (at least I assume it's the last one).
This doesn't happen every time and I'm leery of viewing the clipboard history (observer effect) prior to cmd-c-c. I've only noticed in Safari but that may be because that's where I do most of this type of copying.
Running 10.9 (though this occurred in 10.8 as well), the latest Alfred release (v2.1 (218)), and have all the checkboxes active in the Merging options with 'Separate appended item with space' selected. I'd be happy to perform anything that would help diagnose the problem... I rely on this feature and want to trust it.
Thanks!