Incoming call ringtone duration

[pooky2483]

I have got two Ace+'s (1 mine , 1 wife's), the problem I am having is when I get an incoming call, it rings for ages and then goes to answerphone. When my wifes phone gets a call, it only rings for about 10 seconds before going to answerphone.

I don't know what settings are different to make mine ring longer before the answerphone kicks in compares to my wifes. Has anyone got any ideas?