Well with Breezy Badger (Ubuntu 5.10) you're quite a bit behind the times. You've missed, Dapper Drake Ubuntu (6.06 LTS) and Edgy Eft (Ubuntu - 6.10). Feisty Fawn (Ubuntu - 7.04) will be out next month so if you were going to upgrade you could wait for that, or go for Edgy which is very stable now. There have been a lot of newer kernel versions since then, which kernel do you use? I always install the latest K7 kernel, straight off when installing a distro the do sudo apt-get update.