Vlookup nightmare!

This is driving me mental, please help. Im sure i had nailed the V/HLookup function, but apparently not!

I want to look up a value in a table array on another sheet, and return the value of the cell adjacent to it.
However, i seem to keep returning a #N/A error.

The formula is in cell K3 on 'Quotations Sheet'
The lookup value is cell A3 on 'Quotations Sheet'
The array is A3 to Q922 on 'Job Sheet'
The lookup value appears in Column 2 of 'Job Sheet'

I want to return the corresponding value of column 1, 'Job Sheet'

this is my formula:
=IF(I3="","",IF(I3="CANCELLED", "",VLOOKUP(A3,'Job Sheet'!$A$3:$B$922,1,FALSE)))

I have trierd using the HLOOKUP function instead, to no avail.

I suspect that it is due to the location of the value i wish to return in relation to the column in which the lookup value appears in the array.

Any thoughts?