I'm used to only paste screenshots or screen snippets into mails or design apps and not to save it.
So I have usually checked the Option "Don't Auto Save Captures" (Advanced Tweaking › Miscellaneous Tweaks).
But for a few versions (sorry, can't say the exactly version) the images from clipboard will pasted with 300 DPI instead of 96 DPI.
In Outlook or other DPI-sensing applications the images appear (naturally) far too small.
My default DPI is set to 96 DPI but it will ignored as far as the checkbox for "Don't Auto Save Captures" is checked.
I guess it's a bug, isn't it?