Cisco Jabber Client Not Playing the Ring Tones when it reciveds a call



I have a MC40 (Model MC40N0-SCG3RM0) that is running the Cisco Jabber client version running on a Cisco network.  Customer is saying that the MC40 will not play the RINGTONE but does vibrate.  Customer can play the preview of the different ringtones but again if they recieve a call no ringtone and just vibrates.  They've gone into the settings screen and tried checking and unchecking the Vibrate option but still no ringtones. 


Has anyone encountered this and if so what was the workaround (is this on the CUCM settings somewhere)? 


Note: Customer is currently on 0708 but will be upgrading today to 0811.