Conditional Formatting Excel 2010

[ciwash]

I had set up a spreadsheet to find duplicate values in my group's email addresses. This worked for months and then it started to declare that dates (in another column) were duplicates (which they were). I copied about 100 names and pasted them in a new sheet. Now when I attempt to apply conditional formatting in the new sheet everything is shown as being a duplicate. I guess that it is seeing the @ sign (i.e. joe@gmail) as a duplicate. Why didn't this happen before and how do I stop it now? I can't have two duplicate e-mail addresses.

Thanks

[newdoverman]

Select the column with the email addresses then go to Conditional Formatting, Highlight Cells Rules, Duplicates. Choose the formatting that you want.

[ciwash]

Yes, I understand how to do this. I cleared all of the rules from the entire sheet. Now, all of the e-mail addresses in Texas are listed as being duplicates. I think it has something to do with me creating a new sheet just for Texas (which I deleted). In a test it will identify duplicates when I enter them but insists that everything in Texas is a duplicate. How do I clear this up?

[newdoverman]

Can you send a sample of the problem? This is on the weird side.