|Wow, I didn't realize this has been bothering me for so long... O_o
I did get around to testing enough to figure out (althought thought I wrote it here) that disabling KMS would allow me to suspend/resume normally.
But it took me until I read what slh wrote in this thread to finally solve this problem:
As a suggestion, you should usually leave "Linux command line" in your first screen empty, because KMS capable graphics drivers like intel, nouveau or radeon don't like it and often fail with this set.
After checking my grub setup I found out I had
so I removed it and can now again suspend/resume with the latest kernel.
If I remember correctly, I put that option in there around the introduction of KMS and it had something to do with replacing the old "vga=xxx" option. Something still changed after 3.1-6 that made this option to not do good at least on my system.