I'm using a Acer Laptop 5100 (Athlon 64 TK-53, ATI 1100, 320GB HD, 4GB RAM, Broadcom 4311 Wifi), and I was using for some time Ubuntu 10.04 and later 10.10 64-bit versions without a single freeze. I spent the last 4 days working on a way to make 12.04 LTS work on this machine. Thank god I bought a new HD and saved my original 10.10, because there's no way to make the new LTS run on this machine.
I downloaded and installed both 12.04.2 32- and 64-bit and none worked after the installation. As soon the machine starts, before the login screen, it shows a kernel panic in text mode, after that the machine freezes, and only the power button solves it. I tried Ubuntu 12.04.1 (32- and 64-bit), and they worked fine before the updates. Immediately after the updates, the kernel panic shows up on the login again.
I'm working on a 12.04.1 32-bit without the updates. Could it be related to the new HWE? Or does the new kernel have some issue with my hardware? Thanks for the help.