scotty,
3 complaints out of 100 isn't bad, esp. as you are new to WFP.
are you sure that the windows are spotting

i ask this as i have had customers that think the windows have spotted, when in fact they are still wet. ALSO customers have not realised the spots are on the INSIDE

from when i 1st started i used a round to test out WFP and got 2 bad feedbacks out of 20 custy's + the other half on my own windows, a lot of it was down to technique and getting the system and products i like to work with, but in a very short time i got 100% and no matter how bad the windows are they come up spotless - even the mrs thinks they are great now, i have slowly moved most custy's to WFP now either by doing them when not in

or re explaining the benefits of WFP and have no problems, sometimes when you let the custy's know your changing over they can be ultra critical and see things that are not there
also be aware that in windy conditions dirt can be flicked from 1 window to another if they are close esp. corners of conny's where they join the house, quite often i have done a window, moved along and then looked back to see 'bits' stuck to the pane that were not there before

Some windows will not curtain, but i i dont think thats the problem, just keep rinsing well and keep at it!
Darran