Thanx for your reply!
both computers are on the same network. I tried on windows and linux. for windows putty was used and WinSCP, on linux i used the command line ssh. I get a time-out error on windows, and linux says "no route to host". I am able to ssh to my linux computer from the iphone. Pinging from iphone to computer is also possible. Pinging from computer to iphone doesnt work either. The iphone is able to ping itself though. To me it seems like there is some sort of firewall on the iphone blocking incoming connections or something... Or my wifi is f**** up. haven't had the chance to test on another netowrk though.