Burn Error Help (Log Excerpt Included)

I have been using DVD Shrink with Nero without any problems, but yesterday I decided to check out DVD Decrypter and ImgBurn, which I downloaded. I played around with them for a bit.

I then set out to backup another DVD using Shrink, but it failed three seperate times. This morning, I went to burn that same image using ImgBurn and got the following error. Would you please explain what it means and how this could have occured?

I 10:06:49 Source File Application Identifier: IMGBURN V2.2.0.0 - THE ULTIMATE IMAGE BURNER!
I 10:06:49 Source File Implementation Identifier: ImgBurn
I 10:06:49 Source File File System(s): ISO9660, UDF (1.02)
I 10:06:49 Destination Device: [0:1:0] Philips DVD+RW DVD8601 6D11 (E:) (ATA)
I 10:06:49 Destination Media Type: DVD+R (Disc ID: DAXON-AZ3-00) (Speeds: 2.4x, 4x, 8x, 12x, 16x)
I 10:06:49 Destination Media Sectors: 2,295,104
I 10:06:49 Write Mode: DVD
I 10:06:49 Write Type: DAO
I 10:06:49 Write Speed: MAX
I 10:06:49 Link Size: Auto
I 10:06:49 Test Mode: No
I 10:06:49 BURN-Proof: Enabled
W 10:07:14 DeviceIoControl(FSCTL_LOCK_VOLUME) Failed! - Reason: Access is denied.
W 10:07:14 DeviceIoControl(FSCTL_DISMOUNT_VOLUME) Failed! - Reason: Access is denied.

UPDATE: I have been able to successfully burn a data CD using RecordNow, but still no luck burning DVDs using any number of programs (Shrink/Nero, ImgBurn, RecordNow…).

Again, this is a brand new problem, as of yesterday, I had burned hundreds of discs using Shrink and Nero.

You most likely have something running in the background that has a hold on that drive. Turn it off.