Strange. For me whenever Ctrl is held down when the paste takes place it treats everything as text. So using Ctrl+V always treats it as text but if you normally use Shift+Insert try Ctrl+Shift+Insert instead.
Note that Ctrl must be held down when the paste command is given, not when you press enter on the confirmation box (assuming you use the confirmation box on pasting more than x lines).
Has this just started happening with 6.21? I've only tested it on versions up to 6.2
