I may be communicating my thoughts incorrectly. The copy and paste works. The problem is when I paste it, if there is already text in the entry(text box), even though I have the text in the entry(text box) highlighted, it doe not over-write it but instead it appends to it.
For example, lets say I copied the text "TEXT" and I pasted it into a entry(text box) which already contains the text "NEW". The new text in the entry(text box) is now "NEWTEXT" rather than just "TEXT".