I'm having the same problem on an Amazon Linux server; following the steps above, Ajenti worked flawlessly, but as of a month or so ago, I'm getting the same errors as Brijesh Akbari.

[ec2-user@seneca ~]$ sudo service ajenti start
Starting Ajenti:
Traceback (most recent call last):
File "/usr/bin/ajenti-panel", line 10, in <module>
import ajenti
ImportError: No module named ajenti
failed [FAILED]
[ec2-user@seneca ~]$ ajenti-panel -v
Traceback (most recent call last):
File "/usr/bin/ajenti-panel", line 10, in <module>
import ajenti
ImportError: No module named ajenti