[C] Работа с Xft

Есть wmii(http://omploader.org/vMXBxbg/wmii.tar.bz2) подправленный мною.

gdb bt:

#0 0xb7d37e60 in XftDrawGlyphs () from /usr/lib/libXft.so.2
#1 0xb7d3838d in XftDrawStringUtf8 () from /usr/lib/libXft.so.2
#2 0x0805f8b0 in drawstring (dst=0x8573438, font=0xbfbfbbf0, r={min = {x = 0, y = 0}, max = {x = 4368, y = -1208315190}}, align=EAST, text=0x85ad8f8 "", col=1118481, color=0x0) at x11.c:446
#3 0x0804c6e8 in draw_bar (s=0x85734c8) at bar.c:158
#4 0x080549cc in fs_clunk (r=0x856e5c8) at fs.c:907
#5 0x0806234c in handlereq ()
#6 0x08062172 in handlefcall ()
#7 0x08063312 in handle_conns ()
#8 0x080633b9 in ixp_serverloop ()
#9 0x08056b48 in main (argc=0, argv=0xbfbfc1f8) at main.c:516

Иногда вываливается с таким вот сообщением:

/home/phasma/workspace/wmii/cmd/wmii/wmii.O: fatal error: Xrequest code=55, Xerror code=9
X Error of failed request: BadDrawable (invalid Pixmap or Window parameter)
Major opcode of failed request: 55 (X_CreateGC)
Resource id in failed request: 0x200027
Serial number of failed request: 164
Current serial number in output stream: 185

Program exited with code 01.

Куда копать ?