Christian,

cpuminer versus screen is OK
cudaminer versus screen is not OK


Proof:

root@linux:~# ls -l
total 24
-rw-r--r-- 1 root root 5498 mar  4 14:08 bug.txt
drwxr-xr-x 5 root root 4096 mar  4 12:42 cpuminer-master
drwxr-xr-x 7 root root 4096 mar  4 22:57 CudaMiner
-rw-r--r-- 1 root root  209 lut 28 20:49 cudaminer.conf
-rw-r--r-- 1 root root  334 mar  3 23:20 README.txt

root@linux:~# cpuminer-master/minerd --benchmark
[2014-03-04 23:12:12] Binding thread 0 to cpu 0
[2014-03-04 23:12:12] Binding thread 1 to cpu 1
[2014-03-04 23:12:12] 2 miner threads started, using 'scrypt' algorithm.
[2014-03-04 23:12:13] thread 0: 4104 hashes, 2.70 khash/s
[2014-03-04 23:12:13] thread 1: 4104 hashes, 2.67 khash/s
[2014-03-04 23:12:13] Total: 5.37 khash/s
^C
root@linux:~# screen -dm cpuminer-master/minerd --benchmark; sleep 1; screen -ls
There is a screen on:
        3973..linux  (04.03.2014 23:12:31)   (Detached)
1 Socket in /var/run/screen/S-root.

root@linux:~# screen -r
[screen is terminating]
root@linux:~# CudaMiner/cudaminer --benchmark
           *** CudaMiner for nVidia GPUs by Christian Buchner ***
                     This is version 2014-02-28 (beta)
        based on pooler-cpuminer 2.3.2 (c) 2010 Jeff Garzik, 2012 pooler
            Cuda additions Copyright 2013,2014 Christian Buchner
          LTC donation address: LKS1WDKGED647msBQfLBHV3Ls8sveGncnm
          BTC donation address: 16hJF5mceSojnTD3ZTUDqdRhDyPJzoRakM
          YAC donation address: Y87sptDEcpLkLeAuex6qZioDbvy1qXZEj4
[2014-03-04 23:12:51] 1 miner threads started, using 'scrypt' algorithm.
^C
root@linux:~# screen -dm CudaMiner/cudaminer --benchmark; sleep 1; screen -ls
No Sockets found in /var/run/screen/S-root.

root@linux:~# screen -ls
No Sockets found in /var/run/screen/S-root.

root@linux:~#