Comment 78 for bug 1283938

I just found a working solution for Xubuntu 14.04 updated, uninstalled Gnumeric and Abiword and installed Libreoffice and htop (but I don't think this matters, just want to be clear it is not a completely fresh install). My laptop is an ASUS K55N with AMD A8-4500M Trinity APU and integrated Radeon HD 7640G. Yesterday I tried at least 8 live sessions from different distros (slackware based, gentoo based, arch based, debian based, ubuntu based) with the same results (you can reproduce the bug inside live session).

What I've done so far that works better is to modify /etc/default/grub to:

GRUB_CMD_LINE_DEFAULT="nomodeset acpi_osi="

Then "sudo update-grub"

You'll get a verbose boot because of the nomodeset parameter and, I don't know why or if it is related at all, some degrees hotter laptop (2 C for me). Some Fn keys that I don't use a lot won't work but the ones I use more work great (Vol+/-, Screen off, Screen brightness +/- and Suspend).

This is acceptable for me and I hope this works for someone else.