Vista deletes important back-ups

[kartel]

I noticed in my logs that Vista deleted 4 or 5 backups I had.

I really didnt want that to happen since I am doing testing and have before and after backups.

Now they are gone.

Anyone know how to disble that?

It said "deleting the oldest shadow copy of my drive to save space" like 5 times, I could live with once but all of them? Except 2 ?