I'm using VLOOKUP to pull a value from a range if the number in C33 finds a
match within that range. Here's the function:

=VLOOKUP(C33,$C$249:$D$390,2,FALSE)

This has always worked, and still occasionally works, but for some reason
it's become unreliable. Here's what I'm trying to match it from and to:

Date Name Number #1 Number #2 (function is in 5th column)
Number Date Number #1 Number #2

So the function is searching for Number #1 found in row 1 and trying to find
Number #1 in row 2. If it finds a match, then it pulls Number #2 from row 2
and puts it into the 5th column of row 1.

Any ideas? Thanks in advance!