rtl-tcp-server running on avm-fritzbox

I want to use a rtl-dvb-stick connected to a fritz-box-dsl-router via tcp. Software running on the fritzbox is freetz (www.freetz.org) and cpu-architecture is mips. So I created a makefile and compiled the software without errors. But when I start the software (usb-dongle connected) it throws a usb_claim_interface error -5. rtl_test recognizes the type of stick correctly but throws identical error message. So I started rtl_test with strace - here you can find the output:

http://www.df8oe.de/output.txt

Any tipps for solving the problem are welcome ;)

Best regards df8oe