I use DVD-R for almost a month only thing on it is pictures and word doc so nothing can go to wrong. I do back ups I would say almost 2 times a week. I have use this DVD-R for almost a month and every thing is working okay.Now on the 5 sessions some thing gone wrong . When I click start , computer ,DVD drive it shows no files nothing . It like the files got deleted or it cannot see the files. When I right click on the drive and click on properties it shows 337MB used and that is about right . I don't know what to do it like the files got deleted or it cannot see the files.But the properties it shows 337MB used that about right. I was using windows vista built in burning software.This all stop working after I copy an paste folder to other folder on the disc . I than tried Nero 9 the basic burning software and when in Nero burning software I click on analyze disc it shows 5 sessions and 337MB used and that is about right .I than tried to make copy of bad disc .When I click copy disc it copies it and than tells me to put in new disc and copies to it but it is still not showing up when I click on start , computer ,DVD drive . So it seems it still there but for some reason it cannot see it.