Strange ringtone if I first play a soundfile


I am playing a soundfile and then I dial an internal user. If the user is logged in with X-lite the beeps (ringtone), while ringing the phone, are very strange. Sometimes it beeps very often and sometimes it only beeps 3 times in 20 seconds. If I do not play the soundfile at the beginning, I don’t have this problem.

Does anyone know how to fix this? Or is it possible to use a soundfile in Asterisk instead of the beeps (ringtone) of X-lite?

Thanks in advance!