tomtom one v4: pb sounds & voices

Hello,
excuse me for my bad English, I am French...
I installed(settled) the "navcore 9.510" my tomtom one v4 with the map " France 965-7251 " I used " fast-activate " :OK
my pb is that I have no more the voices or the sounds of alerts radars...
Where from comes my pb?
Who can help me?
For information: I made the try with " navcore 9.540", it's good a little, except that my cable "tmc traffic" is not usable above, not taken into account, and I have no more the display of the maximal speeds when I pass in front of the radar...
so i prefer go back to 9.510

thanks a lot for help me...
if you need more informations do not hesitate to ask me ...

App 9.510.123792.1 OS 547200(2039,4/4/2013) 32MO RAM GPSv1.20 Boot5.5138


@ downunder35m:I tried to download "navcores 8" but the links don't work ...i don't go on the page of download...

hello,
I think of having solved my pb... I put the navcore for version "xl" and I got back the choice of the voices as well as the sounds to schedule for the alerts ...
is it a problem to have "xl" version on a one V4(4N00.006)? Thanks for the answer..
the question: a worry on the navcore for the version 32mb? A bug in my download? In the installation in the tomtom?
I am going to make out a will tomorrow and I hold you informed ...