No Sound on Ubuntu Lucyd 10.04 (HP Mini 110)

When I bought new netbook HP Mini 110-3000 on October, the operating system is XP SP2 but i remember thats i have Ubuntu 10.04 Lucyd CD, from Ubuntu thats have posted to me, then i try beside XP, instaling is work fine normal about 20 minute,i check all VGA,Camera,Wifi is work fine but wheen i try to play MP3 the sound not come out, then i plug extenal speaker,its work fine..ha...whats wrong ..?. then i search In google, after 5 days, i found the blog tell about this problem, i try it and its work fine. thanks so much..and below the step i write here for you all
1. Open terminal
2. Run Bellow command
$ sudo apt-get install linux-backports-modules-alsa-lucid-generic
3. After Finish Restart the Notebook

thanks to http://ordinary-linux-user.blogspot.com