Thanks for your response!
That is exactly what I have, only that my 3600 & 3620 are negative.
Still, 3499+3620 = 3640. Also I do not see any purple error message nor a red pen or anything but the error message still says "GIFI 100 does not balance (GIFI field 2599 does not equal GIFI fields 3499+3620).".
I'm not sure wast GIFI100 is though.