no sound on iPad, Powerbook

[trail 6]

I have an 8 year old Powerbook G4 and a new iPad2. About 4 days ago, computer said new version of iTunes was available. I downloaded and installed it. Now, I have no sound coming from computer. Earphones: no sound. Control panel for sound shows(in black) internal speakers: no sound adjustment possible. Now, I notice that the iPad also is not producing any sound through speaker or earphones. It still beeps. The version of iTunes is: 10.5.3(3). Should I revert to the previous version? How would I do that? Thanks!