Apple has released another update to iTunes designed to improve stability and performance.
From the Update description:
Use iTunes 7.7 to sync music, video, and more with iPhone 3G, and download applications from the iTunes Store exclusively designed for iPhone and iPod touch with software version 2.0 or later. Also use the new Remote application for iPhone or iPod touch to control iTunes playback from anywhere in your home — a free download from the App Store.
iTunes 7.7.1 includes fixes to improve stability and performance.
You can download it now.