QuickTime 7.6.6 for Leopard is recommended for all QuickTime 7 users and according to Apple brings about "general reliability improvements for iMovie." Additionally, the update addresses a long list of security vulnerabilities related to maliciously crafted audio or movie files that could allow attackers to cause crashes or run arbitrary code. The update is available via Software Update or the Apple Support Downloads page. (Free, 68.63 MB)
How to Know Your iPod Model
If you have an old iPod but aren't sure exactly which model it is, check the info at the Web page linked below. You'll find lots of photos and information that will help you determine exactly which model you have.
Visit Identifying iPod Models