Can't open a recordable DVD-R disc

[Mew2]

Hi Everyone,

I have moderate computer experience.

I formated a data disc using a Maxell 4.7Gb DVD-R (16x max speed) disc and Vista's "Live File System", which "allows you to add and erase files, like a USB flash drive." I'm sure I formatted using the default 2.01 UDF, which allows you to access data on both Vista and XP and perhaps other OS. (BTW, There are also 4 other ways to burn a DVD on my computer: Media Player, Windows DVD Maker, NTI CD & DVD-Maker 7, and DVD Decrypter.)

Although I've been using this disc to add/delete files up till now, Windows now refuses to open it. I've restored the Factory Default image in case drivers were corrupted/missing, but still won't open. Windows either comes up with an Autoplay option to format it, as if it is empty, or merely shows percent of the disc that is used when I try to open it via E drive in Computer. When I try to send files to the disc, windows says it can't access it. NTI Backup won't allow me to load files in back-up screen, but it does reveal number of items and size of them. Another guy cudn't open it on his computer with Vista.

I have Vista Home Premium with a DVD/CD-ROM drive (driver: Optiarc DVD RW AD-8530A ATA) that has "DVD-Super Multi double layer (support DVD+R Double Layer/DVD+/-RW)" on an Acer Aspire with Intel Centrino Duo.

I'm desperate to access the data on this this disc because it has literally years of writing that is irreplacable. (Yea, stupid, I thought I had copies on another disc, but didn't.)

Please, can anyone help!?

Thanks in advance.

m2