Using an iPhone 3G has forced me to upgrade my PowerPC-based iMac G5's operating system to Mac OS X version 10.5.4. My Sonos music application has not worked properly since; it can no longer locate music files on internal and external hard disks. I tried upgrading to Sonos 2.6 (build 9166130) but it still doesn't work. Can you help? Vikas Mehra, Mid-Levels DQ: You have certainly approached your problem the correct way by jotting down version numbers and even builds. Unfortunately, I cannot recreate your problem because I don't have the Sonos software. On the Sonos website ( www.sonos.com ), there is a section on how to install the product on Mac OS X version 10.5 'Leopard'. Look it up to see if it is of any help to you. The website also has a feature that sends you an e-mail if the answer to a particular problem is updated. I assume you can access the hard disks you mention from the desktop computer in the normal way? If not, the problem is not just related to Sonos and Leopard. I had no problem running two iPods (32GB and 80GB) on the same computer and with the same iTunes program until I downloaded the latest iTunes software update. The smaller capacity iPod still works as normal when I sync it to my Mac, but when I hook up the other one, the computer freezes. What should I do? Name and address supplied DQ: According to Apple, there are three ways you can sync multiple iPods to your computer. You can set up multiple user accounts, you can set up more than one iPod on the same machine with discrete playlists (Windows personal computers do not support multiple iPods connected at the same time) or you can create a separate library for each iPod. Go to support.apple.com/kb/HT1495 and decide which method is the best one for you. In general, you ought to download iTunes updates whenever prompted. If you want to be cautious, first read what the update is about. It is best to keep an eye on what's going on, especially if you are having a particular problem. Look around for remarks in any online forum about iTunes and read about problems other people are having using multiple iPods. Do be careful about the origin of the site; make certain you can rely on it. Officially recognised sites are far safer than those you have never heard of.