Excel locking up after paste special shortcut used

After using the paste special shortcut (alt + h + v + v) Excel locks up. The boxes with the letter cues stay, while the paste special menu disappears. I am subsequently unable to do anything in excel until I click with the mouse, which seems to release the letter cues and then I am able to use Excel again. Has anyone else experienced this issue before?

I have a screenshot of what this looks like but not sure how to upload it. Can anyone help?