Volume control & network issues after upgrade

Hello,

I have a one year old iMac OS X. I recently I upgraded to 10.6.8 and installed a new graphics tablet. Since then two things have happened.

One - my volume controls F10/F11/F12 stop working after a while. Sometimes five minutes after turning on the computer, sometimes an hour, sometimes all is good till I turn the computer off. The keys haven't been reassigned - the volume change icon appears when I use the buttons however nothing happens. I can change the volume in the System Preferences though.

Two - I started having issues with my network connection. Every now and then, after turning the computer on, I get a message saying "Network Connection Failed" even though I have not changed anything, the router
works fine and other computers in the house can connect without issues. I have used the PRAM option and that fixes the problem till next time. I use a cable connection and connect through the PPPoE service.

Any suggestion on how to fix these issues will be greatly appreciated.
Cheers,
Anna

It's not anymore. To be more specific I bought the iMac in late September of last year which makes it 1 year and two months old (more or less). The issues started appearing so soon after the warranty ended...

Fixed?

The problem seems to have resolved itself after I created a new PPPoE connection and when I uninstalled DIVX (a program which I've updated on the same day). So far I had no issues with either Volume Control or the Network Connection.