ThinkPad A20m running 2.6.17-10-33, all stock, no special patches or packages (FWIW, HWDB 2ad3fb6ba7d8b4d771bf8186b697277f).

At boot, all works well. S3 sleep (suspend-to-RAM) works well and reliably. S4 hibernate (suspend-to-disk) also appears to work well (I've only used it a few times, I tend to use S3 exclusively). I can S3-and-resume repeatedly, with consistent results, as described herein.

Upon resume, "almost all" things work well.

Three remaining problems are:

1) Network isn't visible right away: There is a lag (a few seconds at most) between the machine waking up and Ethernet (eth0 Ethernet) being available. By the time I unlock my screen, the network is available (and I unlock as quickly as I can).

(This appears as an immediate error in Evolution: It attempts to retrieve and cannot resolve mail server addresses. E.g., when I dismiss the Evolution error dialog and immediately send-receive, all is well.)

For me, this is a nuisance more than anything. For someone with an unattended machine waking at a set time, this could be a major stumbling block.

2) No sound. Comes back when I reboot. One exception, booting with noapic and pci=noacpi, see below.

3) Video playback is "blocky", that is, all videos play in extreme slow motion and playback is jumpy. It can take 5-10 seconds to play a single second of video.

Other points of interest:

I am booting with ACPI=force, since thinkwiki.org recommends ACPI on this machine and since the machine appears more responsive when running with ACPI rather than APM. However, all problems described above occur with both APM and ACPI, and all features appear to work equally well under both power management schemes (S3, S4, etc.).

To workaround the problems described above, I've tried booting with various combinations of

    noapic, nolapic, and pci=noacpi

and various combinations of 

    ec_intr=0, lapic, and pci=routeirq

all with ACPI=force.

None of these combos make the slightest difference, behavior is as described in this report. (I haven't yet tried adding pci=noacpi to the second combo set, i.e., with ec_intr=0 and pci=routeirq, but at this point, after dozens of reboots and S3s and resumes, I don't know that I will. Any guidance as to which combo might be worthy of further testing would be much appreciated).

To make it clear, for each set of 3 options, I've booted with all 7 possibilities, and have not been able to detect any improvements. The one exception is that sound was OK upon resume when I booted with noapic and pci=noacpi; other problems remained as described in this report.

One combination made things worse: Booting with noapic nolapic pci=noacpi broke S3, I could not suspend at all. The machine tried, but came back immediately.

Finally, I should note that my /etc/default/acpi-support matches Jakub's, and this by default (it's how the package management system made it). I also tried adding the VBErestore option to /etc/X11/xorg.conf on at least one boot (with ec_intr=0 as Jakub suggested) but that made no difference (I didn't expect it to, since the display does work, it's just playback that is mildly damaged).

Rather than overload the bug report with logs (and I have many), let me know what should be attached specifically to assist with this. Any guidance on boot flags will also be welcome. Thx!