If your backup freezes, stutters, skips, or has some pixelation, it is more than likely due to poor quality media being used. Cheap media is poorly manufactured around the edge of the disc, hence the reason why it mostly skips or freezes from the middle toward the end of the movie. The two main things to consider first are:
1. Is it cheap media that you are using? (ie. some off brand you bought at a local computer store/fair, even a store like Circuit City or Best Buy sells cheap low quality media.)
2. How fast are you burning? - Burn no faster than 4X, might have to go down to 2X with really cheap media.
Open DVD Shrink. Click "Edit", then "Preferences". On the first tab at the top in the drop down box, change it from "DVD-5 (4.7GB) to "Custom" and enter a number of 4200MB (4464MB is burning to the edge of the disc, you want to stay away from the edge as the edge of cheap media (disc's) are poorly manufactured). Screen Shot Below:
Just to add to what was mentioned about labels - I had that problem a long time ago before I knew better NOT to put them on - If you need to get the labels off - spray wd-40 on it, let it sit a few minutes, then it will peel off fairly easily. Then wash off with warm soapy water. I had to de-label about 50 disks all at once trying to save my back-ups - it worked and I have had no problems since.
I have heard some people talking about printables though - they dont seem to have any problems.
But for me - like you said - not pretty but at least it doesnt mess it up - besides - they are just backups so the grimy little hands of toddlers and cousinz wont mess the good stuff up - they help for out of town trips too.