Vlookup / index match against Merged Cells (second query!)

Hi

following on from query
http://www.excelforum.com/excel-form...html?p=3006081

you guys helped fix an issue where it referenced the merged field and repeated the comments from within the merged cell, this was for a text field,
i've amended the formula to reference in a lookup based on a value which meant getting rid of the REPT function which has kind of worked but not 100%, and i'm at a loss to explain why and whether the result is a fluke rather than an actual fix to the problem.

The cells highlighted in yellow are bringing back errors, but only when the vlookup / index match versus the code is 1, 2 or 3, anything else and the formula works fine.

If anyone can explain why this is happening, i would greatly appreciate it!

Thanks, explains the reason why, there had to be some logic behind it.