@Meenal: I got the same error - what I ended up doing is installing the ksoap library separately on the blackberry device - this allows you app to execute with errors.

I'm having a different problem with ksoap/bb:
I've got my app running without issues on the simulator but when I run it on the actual device, it says its sending data to my .net web-service but I don't receive anything on the other end - anyone had this issue?