Works for me (nVidia Corporation GT218 [NVS 3100M]) .... 9 times out of 10.
More accurately, 90 times out of 100, and those 10 times were all since I started using a second monitor via the DisplayPort. I haven't found out yet if there is a deeper pattern - e.g. maybe suspend fails if I unplug first, but not if I "xrandr --output DP-1 --off" first.
Before the second monitor, the only problem I had was that sometime it would resume with a black screen and I had to switch virtual consoles away and back to get it working again.