I've spent *a lot* of time this summer setting up the classroom edubuntu thin client (LTSP 5.2) server, though to tell the truth, it was less than 25% of the time I had to spend over the previous summer and it has/will have lots more functionality, and I expect to 'go live' in class, sooner, to boot!
More than once 'alkisg' has helped me out, see previous posts. The last time was yesterday, my last day to prepare before students arrive and I'm spending 6 hours trying to beat the server into shape. Thanks to alkisg' help I was able to find that the problem was the resolv.conf in the chroot. The symptom was that, when I was chrooted, I was unable to update, all misses with 'apt-get update'. The problem was that the chroot had resolv.conf settings from my house this summer which is where I originally set it up. Upon fixing that, and ltsp-update-image all things were hunky dory. That gave me some time to prepare for my students arriving on Monday. Well, I had to come in today (Saturday) to do lots of the work and got most of it done--even my wife and son came in a bit and helped! Things are looking pretty good :-).