hast du die passende firmware geflasht?
http://www.rcgroups.com/forums/showpost.php?p=10512929&postcount=1
(Update 20.01.2011)OSD for cooperation with external devices ARDUV1_71.hex (as Ardupilot or whatever your design) using simple $A,,,, protocol of data delivery on UART RX pin (read readme.txt for details) , also ARDUmV1_71.hex firmware exactly the same but Artifical Horizon is mixed pitch+roll (that way "m" letter in file name) - so one Horizone bar is moving on sreen .
(Update 28.09.2011)ARDUV1_72.zip , ARDUV1_72 and ARDUmV1_72 in one zip - the same as 1_71 but possible to write from GUI BIN file for regular OSD , firmware respond for VER as number 1.72 - so no errors .
(Update 01.10.2011)ARDUV1_73.zip , ARDUV1_73 and ARDUmV1_73 in one zip file - in this firmware Custom Message have new format $M,x,y,L,E,text, - it is much more handfull for any kind of Arduino IDE to manage sending , all variables are send as tostrig type , not need to carry about HEX format any more .