On a Dell Inspiron 6400 / E1505 I cannot suspend to RAM in Ubuntu Gutsy. Feisty and Fedora Core 6 would both suspend. I have tried to use the acpi-support file from Feisty, but that did not improve the situation. Where can I begin troubleshooting?

More details:
I updated the BIOS to the latest (A17) with no improvement. This is what happens when I select Suspend To RAM in KPowerSave:
The screen goes blank, and the LED on the USB mouse goes off. The bluetooth and power LEDs remain on. The fan is still spinning. There is no response to any keyboard activity. Specifically, I have tried Space, Enter, Power, CTRL-ALT-ESC, CTRL-ALT-DEL, and CTRL-ALT-BKSP but none of these have any effect. I have tried waiting up to ten minutes, and open and close the lid with no change in behaviour. To leave this situation, I must power down by holding the Power button for 4 seconds. The system then performs BIOS POST check, and I can boot via grub.

Note that the problem _may_ be with HAL, as I cannot mount USB devices.

Dotan, have you got any further with this? I have been struggling getting suspend to work on a Dell Inspiron 1501 running Slackware 12. I can get it to suspend but video is scrambled when I resume.

What happens if you enter

?

It seems the problem was the damned ATI X1400 video card, which is unsupported in Ubuntu Gutsy. Feisty works just fine.

the issue might be the fglrx driver is not compatible with the new SLUB allocator in the Gutsy kernel. you needs to make your own kernel package using the older SLAB allocator. this is all far easier than it sounds, just follow the link:

http://blog.vaxius.net/?p=19

this was my fix for my X1300 card, in which i used both kernel suspend-to-ram/disk and user space uswsusp flawlessly

and thank you so very much to the original author, whomever you may be!

That is precisely the problem, and at next install, I will try the solution that you link to. Thanks.