From what I can see, is you have two separate sound devices, … your motherboard sound, which is an Nivida ALC650 on IRQ20, and a separate PCI sound card, which is an ENS1371 (Ensoniq Audio PCI) on IRQ16. Do you have speakers plugged into both sound cards?
The Ensoniq ENS1371 will typically use a kernel module: snd-card-ens1371
The nvidia ALC650 the snd-intel8x0.
Your /etc/modprobe.d/sound file is only setup for the one sound card (the nvidia ALC650).
The tsalsa script suggests your snd-card-ens1371 kernel module is NOT loaded (hence there will be no sound through that device).
How is your Gnome desktop set up? Any chance it is setup to send sound to the Ensoniq as opposed to the nVidia sound device?