Kernel panic on Aspire E1-522 laptop

Hello,

I've got a new Aspire E1-522 laptop originally equipped with Window8 and I've made a fresh installation of OpenSUSE 13.1.

Here the steps:

1. downloaded and burned a new installation-DVD (version x86_64bit) with OpenSUSE 13.1
2. changed the Bios setting from UEFI to Legacy
3. made the CD-ROM boot
4. started the openSUSE installation
   
   1. "use the entire Hard disk" option selected (so windows parttions were completely wiped out)
   2. usual separated partitions applied ( one for swap, one for home, etc)
   
   
5. installation completed with success

At the first run.... boom! "kernel panic - not syncing: watchdog detected hard lockup on cpu 3" :'(
I have restarted the computer several times but the message remains the same. I've gone back to the BIOS but there are not so many options that I can change, just security stuff, boot orders, etc... I've disable the network-boot option (just to save my pride) but nothing changes.
Here the main characteristics of the Acer Aspire E1-522:

• AMD Quad-Core Processor A6-5200 (2.0 GHz)
• AMD Radeon HD 8400 - 512 Mb Graphic card
• 4 GB RAM
• 500 GB HDD

But but but... when I select "openSUSE 13.1 (recovery mode)" at the start screen... it works! So I think that there is no particular problem with CPUs hardware.

Any clue? :(