A bug has been reported in the Ubuntu bug tracker:
When using LANG=sv_SE.UTF-8 I get error messages like "Problem connecting to tracker, urlopen error(111, 'F\xc3\xb6rbindelse v\xc3\xa4gras')", it should read 'Förbindelse vägras'.
From this report:
Steps to reproduce:
1) Make sure urlopen fails (disconnect the network or modify the torrent to point to an invalid url)
2) set LC_ALL=sv_SE.UTF-8
3) Run gnome-btdownload
Version appears to be 0.0.25 (with Ubuntu patches).