No sound on MacBook Pro after 10.6.8 upgrade

Good morning.

I've got an 5,1 model MacBook Pro (aluminium unibody) 4gb RAM, 2.4GHz Core2Duo and it's been working fine up until yesterday when I installed the 10.6.8 Snow Leopard update.

Since then I get no sound through earphones or through the internal speakers.

If I ALT+Click the speaker icon I get two outputs:

Soundflower (2ch)

Soundflower (16ch)

I've no idea what Soundflower is, and a spotlight search just shows up sound.log which refers to

6/23 18:54:29.163 => WoW Version 4.1.0 (14007) Apr 29 2011

So that looks like World of Warcraft (just started WoW and logged in, turned sound off, turned sound on and no sound from WoW either)

Looking at the log in the console and narrowing it down to Soundflower I see:

6/25 10:50:02.974 --- [1] Soundflower (2ch)

6/25 10:50:02.976 --- [2] Soundflower (16ch)

6/25 10:50:02.980 ** Using Driver [0] System Default (Soundflower (2ch))

Anyway, I can get no sound in anything since 10.6.8!

Any ideas?