You've been doing this for years... it can't possibly be Nilvba knowledge is nil, how do I declare it?

Nothing to do with whether 2007 or 2003. It's prompting you because of the Option Explicit line of code and good programming etiquette requires that you ALWAYS declare your variables:This used to work in 2003, so not sure why it wouldn't be declared?
http://www.cpearson.com/excel/variables.htm