MapThis on PSP S&L with FW 37.1 M33-3

Hi,
I am nearly becoming crazy. Since one week I am trying to get the PSP-290 GPS modul running on my PSP Slim&Lite (FW 3.71 M33-3). I tryed now nearly everything. Maybe it just not running because of the FW 3.71 M33-3? Maybe it is not running because it is a Slim&Lite? Maybe MapThis is the wron version (I can open maps. I can Zoom in and zoom out. But when I start "GPS on" mode - nothing happens. I put the baud to 4800 in confic - no change)
Can somebody help me???:confused:

Trompetfish