This device is not based on Texas Instrument AR7 (like other members of the Sinus family), but on an ARM processor (see hardware image below)!
For more info about hardware please see: http://forum.openwrt.org/viewtopic.php?id=2654#p24145 (post #16).
Patches which support the BRN bootloader are needed. You might get them from http://ar7-firmware.berlios.de/, but the device is not listed as officially supported because it is not AR7 based.
TODO: The TableOfHardware entry misses the FLASH ROM size, RAM size (might be wrong), USB Version and requires a general confirmation by someone more with more experience than me. Also is this model really supported by the target.ar7 project? Of course, no.
|Ethernet||ADMtek ADM6996l||10/100 Mbit/s|
|WLAN||ISL3880IK||b/g, 2 antennas, left & right|
It also has a USB Port and different miniPCI WLAN card which can not be seen on the image due to glue. After removing the glue the Chip desc reads ISL 3880 IK.