VLookup Is Confused By Numbers As Text?

I have a hierarchy of system requirements where the hierarchy is represented in "ID" (Column A) by a structure such as:
1: Parent
1.1: Child of 1
1.1.1: Child of 1.1 and Grand-child of 1
etc., you get the picture. My hierarchy is 5 deep at most, there are no spaces, just numbers and periods.

I have to "massage" the spreadsheet to relate the requirements based on their "Name" (Column B) rather than through their "ID" (Column A).
So I created "Parent ID" (Column C) that calculates the ID of the Parent or "0" if there's no Parent.

Now, I need to lookup the value of "Name" for that "Parent ID" and put it in "Parent Name" (Column D).
The formula I have come up with is "=VLOOKUP((C2),$A1:$B1000,2,FALSE)"

As you see in the attached spreadsheet, the only time this works is when the "Parent ID" contains at least two periods, otherwise I get a "#N/A" result.