It seems that there are some encoding issues using read_dta:
I'm working with version 0.2.0.9000. If there are non-ASCII-characters, like german Umlauts (äöüß), they seem to break. It looks like they were treated as UTF-8 by the import-function, but they are actually something like Latin-1 (or similar). I can correct the string by using

iconv(names(attr(*, "labels")), from="L1", to="UTF-8")

PS: With Stata 14 Unicode features have been introduced for the first time: http://www.stata.com/stata14/unicode/
PPS: I can provide a Stata 13 file containing Umlauts. (Stata 14 is not yet available for me.)