unable to run python scripted alert

[sbsbb]

I've made a scripted alert in python, and put it in py app directory
.../splunk/etc/apps/myapp/bin/scripts/scripted_alert.py

in .../splunk/var/log/splunk/python.log I see that it has been triggered with the correct path, and parameters :
2014-08-22 14:37:01,178 INFO ['.../splunk/etc/apps/myapp/bin/scripts/scripted_alert.py', '1', '| stats c | eval ...

When I try to execute it with
.../splunk/bin/splunk cmd python .../splunk/etc/apps/myapp/bin/scripts/scripted_alert.py' with all the parameters from the python.log, it is working...

It seems that splunk is not taking the python interpreter ?
But in my file header I have

#!.../splunk/bin/python
# -*- coding: utf-8 -*-

(... is a substitution / I'm using Splunk 5.0.5)

[starcher]

Most likely your hash bang is off. I believe in this case the full path should work better. if that is a typical Splunk unix install try:

#!/opt/splunk/bin/python

[sbsbb]

this is already the case