Well I did some more digging and it looks like the ltrim/rtrim is doing something because I get different results if I take them out. From what I gathered so far table1.column1 has trailing spaces in some cases and it looks like that causes the differences. Although there are quit a few nulls in column1 and column2 in both tables as well. It really is a mess. I question the data validation on this as well as I think the program wasn't written very well and now we have to deal with it.