RTEMS Version 4.5 TCP/IP connection blocks

[Wilfried Busalski]

Hi cummunity

I've have a big problem.
For an application I need a TCP/IP Connection that reading will not block.
I use the funkcion:

fcntl (fd, F_SETFL, O_NONBLOCK);


An the result is, that the reading is blocked every time.
In Version RTEMS 4.6.2 the source works correct.
What can do to fix this problem???

Regards 
Wilfried Busalski