Anybody know why Excel is not matching these strings?

Anybody know why Excel is not matching these strings?

I have a list of reference keys that I am referencing in a vlookup function:
=VLOOKUP($D1,Sheet1!$G$1:$K$7437,5)
The reference keys (in D1) look like:
A-CD-1203458.01-U
the number in the middle sometimes has a decimal and sometimes does not.
The data in Sheet1 was split at the dashes for easier filtering, and then
I added a column to concatenate it back together (this code is in sheet1
column G):
=CONCATENATE(C1,"-",D1,"-",E1,"-",F1)
Just to make sure it was working, I slapped an IFERROR around it and
discovered that about 30 of my 7000+ records were not found. This confused
me because the data should all be the same. So I tried to use the find
function on the reference key and got nothing found. Then I searched for
just the number on the middle and found the record. everything looks the
same to me, I can't figure out why excel can't find the full key.
What is even stranger to me is that when I copy the cell with the
concatenate formula and paste the value somewhere else, then do a find
all, it returns the pasted result, but not the cell with the formula. I
can't figure it out.
Edit: forgot to mention this is excel 2007.