Missing Logon Sound in Precise & Dash Problem

Just upgraded two computers to Precise this morning to find that there is no logon sound on either. Got perfect sound otherwise in Rythembox etc. Not a major problem you may say but I have gotten to like the Ubuntu Logon sound.

Also, When I have opened the Dash to look at installed apps, the whole computer freezes and I have to force it down to a reboot by the command line or normal method. Both sets of problems are identical on my two computers.

I do like Precise and well done to the Ubuntu Team and Community. I am still a linux newbie so excuse these simple questions but I would like to know how to fix both. Thank you.