Sound problems on Wheezy upgrade

[Lisi Reisz <lisi.reisz@gmail.com>]

The problem has arisen since I upgraded.  Sound was fine in Squeeze.

Now, when I run alsamixergui:

lisi@Tux-II:~$ alsamixergui

I get an error box saying:

alsamixer: function snd_mixer_load failed: invalid argument

No pulseaudia is installed. 

I get the same problem on a fresh install of Wheezy on my husband's box.

on-board sound on my box: chipset Intel Z77 Express chipset

root@Tux-II:/home/lisi# lshw | grep snd
             configuration: driver=snd_hda_intel latency=0

I have no idea where to look.  I have googled the error message, and get a 
lot of hits.  It is obviously a common error, but I could see no solutions 
that seemed to fit my situation.  Probably couldn't see the wood for the 
trees. :-(

Two people had succeeded by purging everything Alsa related and installing 
Alsa from upstream, though one of them had to run snddevices after every 
boot.  Hardly satisfactory, especially on my husband's box.

Any suggestions, please?  Ought I to purge and install from upstream?  In 
general, I prefer to stick to Debian versions.

Thanks for any help,
Lisi