V jazykovom subore, ktory niekto editoval, su na konci riadiace znaky CRLF, treba ich v text editore nahradit len riadiacimi znakmi LF. Riadici znak CR je tam naviac. CRLF je bezne odEntrovanie konca riadku, kde niekto pouzije Enter. Pouzite napriklad Notepa++ a zapnite si zobrazovanie riadiacich znakov, uvidite, co tam je.
Probably it is a codepage issue built into the device. I know that from the past when eastern european languages could not be mapped fully since some characters were missing. I know that there are some region specific Garmin releases since chinese characters are not supported on european watches for instance. If you bought a Garmin in Czech republic having this behavior, I would contact Garmin Support and ask them is they have a solution.