Seemingly all of a sudden my Windows XP machine with the latest version of iTunes was running out of hard drive space. Last time I checked a couple weeks ago I had at least ten gigs free. I haven't been downloading any large files or installed any new software for some time so I'm sort of confused what is consuming this space. I first got the low disc space warning after I had restored my iPhone 4 32gig from 4.1 back to 4.0.1 successfuly and was restoring from backup. It wouldn't let me restore from backup because of this. I freed enough memory to do the restore and it showed I had just over 1 gig free. After work this morning I synced my phone and all of a sudden I was out of memory again! After digging around a bit I found that my Application Data>Apple Computer>Mobile Sync>Backup folder was 32 gigs! That can't be right, can it? I did hit a few speed bumps when I was going through the whole restore back to 4.0.1 (long story) and had to start over a few times, as it were. When restoring from backup I was offered several different restore options, even some from my old 3G. I'm copying that 32 gig backup file to my external and then I'll erase it and re-backup my phone and see what happens. Does anyone know how big the average backup file should be or have any idea what might be going on?