There are 1.81 apps available on the site. New firmware is usually enlisted in the topic: http://cowon.at.ua/forum/30-49-1.
The official site link: http://download.cowon.com/data/C08/Q5/1_81/COWON_Q5_1.81_appz.zip.
I tried switching firmware's language from my native russian to english, and it seems to be working properly.
The only thing confusing is that it still indicates firmware's language as russian. Maybe you should consult with YDean or djmorganfreeman before installing this.
One more thing. Some apps could not be translated fully from korean. Due to this, the calendar in 1.81 is displaying s*** instead of numbers. I copied Q5W_calendar.exe from v1.51 and discarded 1.81's version. Now calendar works like it should. The same thing with text viewer. I don't use it much, the AlReader is more convenient, so i don't know what new features I missed by replacing 1.81's version with 1.51's.
