Excel 2010 Cannot paste into a form textbox

I have a textbox within a frame on my form. A user wants to copy and paste data into this textbox. They are unable to do so. They can copy the when but they try a right click or CTRL + V nothing happens

I've looked at the text box properties and don't see anything that is preventing this.

The data they are copying is Arial 10. The Textbox is formatted as Arial Regular 10.

Is there something on the form or frame that is preventing the paste feature from not working.

Thanks for the help..........

If Locked property = False then no entry would be possible. Font style does not paste. The Font property in it governs so it is like PasteSpecial as plain text

Locked = false. I changed it to True and was unable to enter anything in the TextBox. Once I changed it back to False, I could at least key data in the textbox. Thanks..

Of course. It was the only reason I could think of. Something else may have cleared the clipboard. Shift+Insert can sometimes work but I suspect that something else is going on for that user.

If you can duplicate the problem, you can post the workbook as an attachment.