When the Droid first came out I tried syncing my Itunes songs & podcasts (audio & video) to the Droid using drag & drop as well as DoubleTwist. I had over 1000 of songs, about 10GB of data to send over. Initially, I experience lock-ups partway through long sync sessions, and I eventually narrowed the problem down to the Droid timing out during sync. Back then one of the options for screen timeout was "Never". The 2.01 update took that option away (30 min is now the max).
After recently peforming a master reset I now have to re-load all of my media. I tried Motorola Media Link and DoubleTwist, but I still get the lockups when I get near 30 minutes. I have enabled the option in Apps>Development fo the screen to say on when charging, but that hasn't helped.
I just installed an app from the market that forces the screen to stay awake when I toggle the app. When time permits I plan to see if this app will help resolve my issue. I hope that Android 2.1 (whenever it comes out) will fix the problem. In the meanwhile, I was wondering if any of you have had success or failure using a app to keep the screen awake during sync.