Comment 52 for bug 198218

On a Dell Inspiron 9400 with snd-hda-intel, I get the same problem.

There is an interesting effect where from a fresh boot, the suspend/resume works fine. Sound works and everything is great. The problems seem to be after I have run Banshee using Gstreamer.

Note that I can happily run mplayer or flash videos with sound time and again and then suspend and resume apparently fine.

Running sudo /sbin/alsa force-reload will enable Banshee to play audio again. At this point, Mplayer no longer works, with the warning:
AO: [pulse] Failed to connect to server: Connection refused
Could not open/initialize audio device -> no sound.