occasional sound loss

Occasionally, sound would stop playing while running mplayer or nspluginplayer. Restarting mplayer, or other programs that play sound, there would still be no sound, and no error. The problem solves itself after I kill all the programs that are playing sound and waiting for a while. This is still annoying though.

sudo lspci -v | grep -A 20 -i audio
00:1b.0 Audio device: Intel Corporation 5 Series/3400 Series Chipset High Definition Audio (rev 06)
Subsystem: Lenovo Device 215e
Flags: bus master, fast devsel, latency 0, IRQ 43
Memory at f2520000 (64-bit, non-prefetchable) [sizeK]
Capabilities: [50] Power Management version 2
Capabilities: [60] MSI: Enable+ Count=1/1 Maskable- 64bit+
Capabilities: [70] Express Root Complex Integrated Endpoint, MSI 00
Capabilities: [100] Virtual Channel
Capabilities: [130] Root Complex Link
Kernel driver in use: HDA Intel
Kernel modules: snd-hda-intel

What other information should I provide about my system?