[xmonad] UTF8 output from xmonad mangled

Hi folks, I'm using xmobar as my status bar and have problems to get UTF8 characters to display correctly. I did the following tests: 1. Start xmobar, reading input from stdin. Type in some unicode characters. Xmobar displays them fine. 2. Add some unicode characters to my loghook in xmonad. Things come out garbled. 3. Instead of piping to xmobar, make xmonad write to a file. The file contents are also garbled. To be more precise, they are exactly what xmobar shows me in the second test. So this seems like the problem is on xmonad's end, not xmobar's. I'm running the latest darcs version of xmonad. Any ideas what could be causing this? Thanks, Norbert