I use Windows Vista x64 and regularly use command line windows, for instance CMD.EXE. I have enabled QuickEdit Mode (and Insert Mode and AutoComplete), to be able to quickly copy and paste text from and to console windows.
Copying (select block, Enter) works fine. Pasting (right click) text also works, as long as it has been copied inside a console window. When I copied the text somewhere else however (in an editor, browser or whatever, or using CLIP.EXE), pasting into a console window does not work! :-(
This applies to all kinds of console windows: CMD.EXE, Cygwin bash.
Using the menu to Edit, Paste does not do anything either, so it's not a mouse thing. I also tried elevating CMD.EXE. I can copy/paste freely between console windows of all sorts: cmd/bash, elevated/normal, x64/x86...
I'm sure it did work on this machine until relatively recently. What could have happened? Some Windows Update perhaps?