pts: 0000000000000000

I've got a (virtual) server running Slackware on (physical) server running Centos.

In my ssh session (in Slackware box), just to check whether the files I downloaded last night have been finished, I do ps ax | grep wget,  and violaa:
ayu@slackware-cluster:~$ ps as | grep wget 
1001 18715 0000000000000000 0000000000000000 0000000000000000 0000000000000000 S+ pts/1 0:00 grep wget 
ayu@slackware-cluster:~$ ps as | grep wget 
1001 18717 0000000000000000 0000000000000000 0000000000000000 0000000000000000 R+ pts/1 0:00 grep wget 
ayu@slackware-cluster:~$ ps as | grep wget 
1001 18719 0000000000000000 0000000000000000 0000000000000000 0000000000000000 S+ pts/1 0:00 grep wget 

I screwed the pts? Obviously, this guy here had the same glitch. The system ran just fine afterwards (no silly 0s), it was just fun to watch some erroneous output. :D