Highlight duplicates not working in excel 2010

I use spreadsheets in Excel 2007 and have a serial number column set to highlight duplicates. It works perfectly.

I am training a co-worker who has Excel 2010. If I copy an entire row and insert it, I get a duplicate row as expected. Now there is a duplicate seial number, but Excel 2010 refuses to highlight it. If I type a duplicate serial number in that column it will be highlighted. If you paste or insert it will not be highlighted.

It is an issue because I will often copy a row (20 or so coulmns) and insert it multiple times, then insert the correct serial numbers. I may be doing this to enter 24 new serial numbers. I need to know right away if there are duplicates.

This works in 2007 but not in 2010.

I Dnt know much about your problem but have you tried pasting using the 'Paste Special' Function?

That does work, but adds another step. It is very frustrating when things that worked really well in the version you are used to no longer work in the new version.

I have to add rows to the spread sheet so I always copy and insert. This creates a new identical row so all I need to change is the serial number. The other 20 or so columns with data like addresses and model numbers can stay the same. There are thousands of rows in the spreadsheet and I may need to add a few or 2 dozen new rows somewhere in the middle. Copy and insert worked well.
Now I will have to create blank rows,then copy and paste special.

You can copy a row as you normally would. Then on the left most select the row where you want it inserted then right click and paste special. No need to insert first.

I need to add new rows as opposed to paste which would over write the existing data. This is why I use insert. Unfortunately when you copy and insert you do not get options to insert just the values like you do with the paste function.