This has happened to me a couple of times. I will have something that has a point at the very last part of the print and that point will not print. Simplify slows way down for the point and printer will clog or just not print the last 1/8". Maybe I should keep the speed constant. thanks.
It's also possible that your printer's buffer gets overridden when you get to the end of a print - I've seen some printers that do this. Try adding M400 as the first line of your ending script.