I'm running Ubuntu 12.04 (Precise Pangolin, I believe) on my Toshiba A305-S6872. After the initial install, everything was mostly great. However, after the most recent set of upgrades, the suspend to RAM functionality has stopped working. What happens is that the computer suspends successfully, but upon resume is totally unresponsive. I've tried pressing Ctrl-Alt-F1 to get to a console session. I've even tried using the "magic" Alt-SysRq shortcuts baked into the kernel. Nothing works. The only way to get a responsive machine agains is to hold down the power button and hard reboot the thing.
As I said earlier, this is new behavior - suspend to RAM worked when I initially installed Ubuntu. My question is, how do I figure out which package or update is causing this regression, so I can file an accurate bug report?