I've been using vlookup to combine reports extracted from our erp system. I
open them as text (.csv) files into Excel.

most of the time vlookup works ok, but every now and then I just can't get
the function to find anything, resulting #N/A. In these cases it starts
working if I go to edit the lookup_value cell and do nothing else than press
enter (i.e. pressing F2 and enter). But with 15k rows it is not fun...

I guess it has something to do with datatypes of the lookup_value and the
table_array? I have tried to modify the type, but it doesn't seem to have
effect.