uart and ft800 incorrect data

[mototest]

Hi all
I have small problem,
my computer send data with pauses 100ms, when I don't click any button etc., all works ok,
but always when I click evebutton or evetoggle are received incorrect data by uart (only for this moment)
I see it because I use CRC , how I can resolve it, or how I can disable uart when I click buttons ?
I use hardware uart in atxmega128a1

Thanks
Bob